A316721 Expansion of Product_{k=1..9} (1+x^(2*k-1))/(1-x^(2*k)).

1, 1, 1, 2, 3, 4, 5, 7, 10, 13, 16, 21, 28, 35, 43, 55, 70, 86, 105, 129, 159, 193, 231, 279, 338, 403, 477, 568, 675, 795, 932, 1094, 1284, 1497, 1736, 2016, 2340, 2700, 3105, 3573, 4106, 4699, 5363, 6118, 6972, 7921, 8974, 10163, 11500, 12974, 14606, 16435, 18471

Offset

0,4

Links

Seiichi Manyama, Table of n, a(n) for n = 0..10000

Mathematica

nmax=50; CoefficientList[Series[Product[(1 + x^(2 k - 1)) / (1 - x^(2 k)), {k, 1, 9}], {x, 0, nmax}], x] (* Vincenzo Librandi, Jul 12 2018 *)

Prog

(PARI) N=99; x='x+O('x^N); Vec(prod(k=1, 9, (1+x^(2*k-1))/(1-x^(2*k))))

Crossrefs

Product_{k=1..b} (1+x^(2*k-1))/(1-x^(2*k)): A000012 (b=1), A004525(n+1) (b=2), A000933(n+5) (b=3), A089597 (b=4), A014670 (b=5), A316718 (b=6), A316719 (b=7), A316720 (b=8), this sequence (b=9), A316722 (b=10).

Cf. A316675.

Sequence in context: A316718 A316719 A316720 * A316722 A106507 A006950

Adjacent sequences: A316718 A316719 A316720 * A316722 A316723 A316724

Keyword

nonn

Author

Seiichi Manyama, Jul 11 2018

Status

approved