A294624 Number of partitions of n into distinct generalized octagonal numbers (A001082).

1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 1, 1, 0, 1, 1, 0, 0, 0, 2, 2, 0, 1, 1, 1, 1, 0, 2, 2, 0, 0, 1, 2, 1, 0, 1, 2, 1, 1, 2, 2, 1, 0, 2, 3, 1, 1, 2, 2, 1, 0, 1, 3, 2, 2, 3, 1, 1, 1, 3, 5, 2, 2, 3, 2, 2, 1, 3, 5, 2, 1, 3, 3, 2, 1, 3, 6, 3, 1, 3, 4, 3, 1, 4, 7, 3, 0, 3, 6, 4, 1, 2, 7, 5, 2, 4, 5, 5, 2

Offset

0,22

Links

Table of n, a(n) for n=0..100.

Eric Weisstein's World of Mathematics, Octagonal Number

Index to sequences related to polygonal numbers

Index entries for related partition-counting sequences

Formula

G.f.: Product_{k>=1} (1 + x^(k*(3*k-2)))*(1 + x^(k*(3*k+2))).

Example

a(21) = 2 because we have [21] and [16, 5].

Mathematica

nmax = 100; CoefficientList[Series[Product[(1 + x^(k (3 k - 2))) (1 + x^(k (3 k + 2))), {k, 1, nmax}], {x, 0, nmax}], x]

Crossrefs

Cf. A001082, A024940, A279281, A290942, A294622, A294623.

Sequence in context: A174294 A089385 A124407 * A290531 A206442 A137581

Adjacent sequences: A294621 A294622 A294623 * A294625 A294626 A294627

Keyword

nonn

Author

Ilya Gutkovskiy, Nov 05 2017

Status

approved