A322855 Number of compositions (ordered partitions) of n into heptagonal pyramidal numbers (A002413).

1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 14, 18, 23, 29, 36, 44, 53, 64, 78, 97, 121, 151, 188, 233, 287, 352, 431, 530, 654, 809, 1002, 1241, 1535, 1895, 2335, 2876, 3544, 4371, 5396, 6666, 8237, 10176, 12564, 15504, 19126, 23594, 29111, 35928

Offset

0,9

Links

Table of n, a(n) for n=0..54.

Eric Weisstein's World of Mathematics, Heptagonal Pyramidal Number

Index entries for sequences related to compositions

Formula

G.f.: 1/(1 - Sum_{k>=1} x^(k*(k+1)*(5*k-2)/6)).

Mathematica

nmax = 54; CoefficientList[Series[1/(1 - Sum[x^(k (k + 1) (5 k - 2)/6), {k, 1, nmax}]), {x, 0, nmax}], x]

Crossrefs

Cf. A002413, A279223, A282582, A322340, A322799, A322803, A322853, A322854, A322856.

Sequence in context: A367800 A291146 A023358 * A322803 A322800 A061379

Adjacent sequences: A322852 A322853 A322854 * A322856 A322857 A322858

Keyword

nonn

Author

Ilya Gutkovskiy, Dec 29 2018

Status

approved