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## #26 2011-05-19 08:22:08

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

### Re: Let's make triangular numbers.

351
a triangle with 26 rows, pair them up for 13 pairs of 27.
270 + 81 = 351, yup.

igloo myrtilles fourmis

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## #27 2011-05-19 14:41:09

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

378

Is the sum of two other traingular numbers.

378 = Triangular(12) + Triangular(24)

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.

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## #28 2011-05-25 00:02:10

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,939

### Re: Let's make triangular numbers.

I see what youre up to here.

Everyone is holding off from posting because you all want to hit post #31.

So Im going to have it this way.

The North Circular Road around  inner London = 406

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #29 2011-05-25 00:04:40

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,939

### Re: Let's make triangular numbers.

Then

(root(4) x 10 + (4 + 5)) x 3 x 5 = 435

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #30 2011-05-25 00:06:44

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,939

### Re: Let's make triangular numbers.

Triangular  45 with a triangular 6 between = 465

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #31 2011-05-25 00:08:01

bob bundy
Moderator
Registered: 2010-06-20
Posts: 7,939

### Re: Let's make triangular numbers.

496  Arrrrhh!  Thats perfect!

Bob

Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei

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## #32 2011-05-25 02:56:40

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

528

2^9 + 2^4 = 528

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.

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## #33 2011-05-25 08:29:05

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Let's make triangular numbers.

561

if HCF(561,b)=1 then b^560 is congruent to 1 modulo 561

Last edited by anonimnystefy (2011-08-14 22:39:57)

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #34 2011-05-25 09:10:04

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

595

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.

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## #35 2011-05-25 09:15:28

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Let's make triangular numbers.

630=2*3*3*5*7=97+101+103+107+109+113 which are consecutive primes

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #36 2011-05-25 09:50:48

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

666

The mark of the beast.

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.

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## #37 2011-05-25 22:19:21

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Let's make triangular numbers.

703-a Kaprekar number

Last edited by anonimnystefy (2011-05-25 22:22:06)

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Online

## #38 2011-08-14 09:28:39

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Let's make triangular numbers.

740-a non-totient number

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Online

## #39 2011-08-14 18:34:26

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

Hi;

741 a triangular number.

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.

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## #40 2011-08-14 22:34:40

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Let's make triangular numbers.

oh yes you are right

catching up:
780-also a hexagonal number,Harshad number,sum of ten consecutive primes:

780=59 + 61 + 67 + 71 + 73 + 79 + 83 + 89 + 97 + 101

8+2+0|820

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

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## #41 2012-07-04 04:58:55

John E. Franklin
Member
Registered: 2005-08-29
Posts: 3,588

### Re: Let's make triangular numbers.

861 = 41 + 820

41 by 21 = 800 + 1 + 40 + 20

igloo myrtilles fourmis

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## #42 2012-07-04 05:24:12

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

Hi;

903 not a 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.

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## #43 2012-07-04 05:27:26

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Let's make triangular numbers.

946-not a prime either.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Online

## #44 2012-07-04 05:29:22

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

990 almost a 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.

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## #45 2012-07-04 05:33:24

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Let's make triangular numbers.

1035-first triangular number greater than 1000.

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Online

## #46 2012-07-04 05:36:30

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

1081 also not a 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.

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## #47 2012-07-04 05:40:46

anonimnystefy
Real Member
From: Harlan's World
Registered: 2011-05-23
Posts: 16,030

### Re: Let's make triangular numbers.

1128-not not a not-prime

Here lies the reader who will never open this book. He is forever dead.
Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Online

## #48 2012-07-04 05:42:33

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

1176 add 600 and it has meaning today!

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.

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## #49 2012-12-13 18:10:59

mathaholic
Member
From: Earth
Registered: 2012-11-29
Posts: 3,251

### Re: Let's make triangular numbers.

Mathaholic | 10th most active poster | Maker of the 350,000th post | Person | rrr's classmate

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## #50 2012-12-13 20:44:41

bobbym
bumpkin
From: Bumpkinland
Registered: 2009-04-12
Posts: 109,508

### Re: Let's make triangular numbers.

The next triangular number is 1275.

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.

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