I have downloaded the first book Combinatorial Mathematics for Recreation - N. Vilenkin.

I will read it and post any doubts that I have on this forum.]]>

Here are some. The first six are good to learn from.

Combinatorial Mathematics for Recreation N. Vilenkin

Applied Combinatorics Alan S. Tucker

Concrete Mathematics Knuth, Graham and Patashnik

Discrete Mathematics Elementary and beyond. Lovasz

Introduction to Combinatorics Alan Slomson

Introduction to Combinatorial Mathematics C.L. Liu

Introductory Combinatorics 5th ed. Richard Brualdi

An Introduction to Combinatorially Analysis John Riordan

Discrete and Combinatorial Mathematics Ralph Grimaldi

Enumerative Combinatorics volumes 1 and 2 Richard P. Stanley

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