A292415 a(n) = [x^n] Product_{k>=1} (1 / (1 - 2^n*x^k)).

1, 2, 20, 584, 70160, 34670624, 69827571776, 567417533153408, 18519367937794769152, 2422592506675732350501376, 1268890961666701371908767613952, 2659755334364276805914758224778627072, 22306192375831301664022382396371369078034432

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..57

Formula

a(n) ~ 2^(n^2).

Mathematica

nmax = 15; Table[SeriesCoefficient[Product[1/(1-2^n*x^k), {k, 1, n}], {x, 0, n}], {n, 0, nmax}]

Prog

(PARI) {a(n)= polcoef(prod(k=1, n, 1/(1-2^n*x^k +x*O(x^n))), n)};
for(n=0, 20, print1(a(n), ", ")) \\ G. C. Greubel, Feb 02 2019

Crossrefs

Cf. A292414, A292416.

Sequence in context: A350794 A009399 A275779 * A197743 A009182 A015207

Adjacent sequences: A292412 A292413 A292414 * A292416 A292417 A292418

Keyword

nonn

Author

Vaclav Kotesovec, Sep 16 2017

Status

approved