Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**satish kumar singh****Guest**

danaj wrote:

In the example for "is 281 prime" you did:

1. find squre root of number near about it is 17

2 17*=Pn*=510510

3 Ip17 =number not divisible by 2,3,5,7,9,...17then: prime= Ip17-Pn* where IP17 started at 510513, and Pn* was 510510.

For the example "111,111,111,111,111" (decimal), I get a square root of 10540925. Step 2 as well as the prime generation says to use Pn*=10530925#. That came out to 4,576,061 digits for me. The number in "No of Ipn sub series" is going to be similarly titanic. What is different about this example from the 281 example?

You have to either store these or calculate them, and either way I don't see how you can say "don't worry about time [...] to find them." Why not just precalculate the primes directly if we get to discount the time and/or space?

then: prime= Ip17-Pn* where IP17 started at 510513, and Pn* was 510510.

Just for General way

For the example "111,111,111,111,111" (decimal), I get a square root of 10540925. Step 2 as well as the prime generation says to use Pn*=10530925#. That came out to 4,576,061 digits for me. The number in "No of Ipn sub series" is going to be similarly titanic. What is different about this example from the 281 example?

hi

First of all I would like to clear for two type of test of prime number

1- Finding for any single prime number( it is not testing ).

( Prime number = Ipn element-Pn*(only values i.e multiplication) )

Ex-

510751(Ipn) - 510510 (P17) = 241 ( prime )

467 (Ipn) - 450 (P5) = 17 ( prime )

469 (Ipn) - 450 (P5) = 19 ( prime )

2- Second group testing.( I use Ipn Set it is well defined itself and in A.P ). So can be operate very easily. Second Ipn set tends to zero% in compression of natural number in fact it will give only prime number in higher range of prime table)

Ex. I33,5,7,9,11,---infine

Ex I5----5,11,17,23
.. infine

7,13,19,25
. Infine

In general Go to post#15

You have to either store these or calculate them, and either way I don't see how you can say "don't worry about time [...] to find them." Why not just precalculate the primes directly if we get to discount the time and/or space?

Thanks

**satish kumar singh****Guest**

danaj wrote:

In the example for "is 281 prime" you did:

1. find squre root of number near about it is 17

2 17*=Pn*=510510

3 Ip17 =number not divisible by 2,3,5,7,9,...17then: prime= Ip17-Pn* where IP17 started at 510513, and Pn* was 510510.

For the example "111,111,111,111,111" (decimal), I get a square root of 10540925. Step 2 as well as the prime generation says to use Pn*=10530925#. That came out to 4,576,061 digits for me. The number in "No of Ipn sub series" is going to be similarly titanic. What is different about this example from the 281 example?

You have to either store these or calculate them, and either way I don't see how you can say "don't worry about time [...] to find them." Why not just precalculate the primes directly if we get to discount the time and/or space?

then: prime= Ip17-Pn* where IP17 started at 510513, and Pn* was 510510.

Just for General way

hi

First of all I would like to clear for two type of test of prime number

1- Finding for any single prime number( it is not testing ).

( Prime number = Ipn element-Pn*(only values i.e multiplication) )

Ex-

510751(Ipn) - 510510 (P17) = 241 ( prime )

467 (Ipn) - 450 (P5) = 17 ( prime )

469 (Ipn) - 450 (P5) = 19 ( prime )

2- Second group testing.( I use Ipn Set it is well defined itself and in A.P ). So can be operate very easily. Second Ipn set tends to zero% in compression of natural number in fact it will give only prime number in higher range of prime table)

Ex. I33,5,7,9,11,---infine

Ex I5----5,11,17,23
.. infine

7,13,19,25
. Infine

In general Go to post#15

You have to either store these or calculate them, and either way I don't see how you can say "don't worry about time [...] to find them." Why not just precalculate the primes directly if we get to discount the time and/or space?

Thanks

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

1- Finding for any single prime number( it is not testing ).

Hmmm, can you find all the primes between

111 111 111 111 000 and 111 111 111 111 999?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**satish kumar singh****Guest**

bobbym wrote:

1- Finding for any single prime number( it is not testing ).

Hmmm, can you find all the primes between

111 111 111 111 000 and 111 111 111 111 999?

Yes why not sure up to 16 digits

br

satish

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Please list them for me. Can you?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**satish kumar singh****Guest**

bobbym wrote:

Please list them for me. Can you?

sure i will but i will have to work for that.It will take time bcz i have less time these day.But i will show you result.

Br

Satish

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Okay, that would be good.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**satish kumar singh****Guest**

bobbym wrote:

Okay, that would be good.

sorry it will take long time to find 15digits prime no on excel, will have to make code for it.

i had done it to 10 digits only.

Br

satish

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Hi;

Let me see it when you have it.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**satish kumar singh****Guest**

bobbym wrote:

Hi;

Let me see it when you have it.

i will have to check 15 digits number (7777) times to get result.

br

Satish

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

If you do not have a math proof, the next best thing is some numerical evidence. If you do not have either then you have nothing.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**satwnz****Member**- Registered: 2011-08-13
- Posts: 14

Odd Prime numers always yiels a small prime number ( in proper range ).

Every odd Prime numers yiels a small prime number ( in proper range ).

Prime Number MOD 30 (5< p<25 ) MOD 210 (7< p<49 ) Mod 2310 (11< p<121 )

2,347 7 37 37

2,351 11 41 41

2,357 17 47 47

4,637 17 17 17

4,639 19 19 19

4,643 23 23 23

4,657 7 37 37

4,663 13 43 43

6,947 17 17 17

6,949 19 19 19

9,277 7 37 37

9,281 11 41 41

9,283 13 43 43

This directly Means if you have big prime number with help of mod smaller can be find out.

*Last edited by satwnz (2015-03-16 02:27:13)*

IF there is problem there is solution

Offline

We have many number theorists here...

Is 9831655609 prime?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

It is prime.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

bobbym wrote:

If you do not have a math proof, the next best thing is some numerical evidence. If you do not have either then you have nothing.

Not true. I have some carrots.

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Do you know what an Otark is?

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

No, I am afraid of jargon?

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**bobbym****bumpkin**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 109,606

Not jargon it is.

**In mathematics, you don't understand things. You just get used to them.****If it ain't broke, fix it until it is.**** Always satisfy the Prime Directive of getting the right answer above all else.**

Offline

**satwnz****Member**- Registered: 2011-08-13
- Posts: 14

Agnishom wrote:

We have many number theorists here...

Is 9831655609 prime?

9831655609 ( MOD 30)=19 PRIME

IF there is problem there is solution

Offline

Very good.

I suppose 49 is prime too, by the same logic?

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

I'm not crazy, my mother had me tested.

Offline

**satwnz****Member**- Registered: 2011-08-13
- Posts: 14

Agnishom wrote:

Very good.

I suppose 49 is prime too, by the same logic?

No dear How you have calcluted can u explain...you have made mistake.:cool

IF there is problem there is solution

Offline

**satwnz****Member**- Registered: 2011-08-13
- Posts: 14

satwnz wrote:

Agnishom wrote:Very good.

I suppose 49 is prime too, by the same logic?

No dear How you have calcluted can u explain...you have made mistake.:cool

take example of consecutive prime there mod with 30,210,2310 will give prime in range .Range is given in table.

consecutive prime MOD 30 (5 < prime< 25 ) MOD 210 ( 7 < prime < 49 ) Mod 2310 (11< pprime < 121 )

2,333 23 23 23

2,339 29 29 29

2,341 1 31 31

2,347 7 37 37

2,351 11 41 41

2,357 17 47 47

2,371 1 61 61

2,377 7 67 67

2,381 11 71 71

2,383 13 73 73

2,389 19 79 79

2,393 23 83 83

2,399 29 89 89

2,411 11 101 101

2,417 17 107 107

2,423 23 113 113

2,437 7 127 127

2,441 11 131 131

2,447 17 137 137

now ok, if we have big prime we can find out smaller one.

in general big primes yeilds smaller one........:d

IF there is problem there is solution

Offline

**satwnz****Member**- Registered: 2011-08-13
- Posts: 14

Hi,

Wants some suggestion on

If mod(Prime B ,Pn*)>1 then result will be Small Prime A in proper Range.

where Pn* is multiplication of all prime number less the nth prime number Ex 6,30,210,2310,30030,510510,9699690,….Pn*. Prime B>Pn*

Range of Prime B

3*=6 gives prime 3>=p<9

5*=30 gives prime 5>=p<=25

7*=210 gives prime 7>=p<=49

11*=2310 gives prime 11>=p<=121

.

.

.

.

Pn*=...gives prime Pn*>=p<=(Pn)^2

Ex

6 gives prime 3>=p<9

Mod (23,6)= 5 ; Mod (29,6)= 5 ;

30 gives prime 5>=p<=25

Mod(157,30)=7: Mod(163,30)=13: Mod(167,30)=17; Mod(173,30)=23

210 gives prime 7>=p<=49

Mod(223,210)=13; Mod(227,210)=17; Mod(229,210)=19; Mod(233,210)=23; Mod(239,210)=29;Mod(241,210)=31; Mod(251,210)=41

IF there is problem there is solution

Offline

**mr.wong****Member**- Registered: 2015-12-01
- Posts: 239

Hi satwnz ,

I suggest you to read through my thread " An algorithm to generate primes " .

You will find our similarity and difference .

Offline