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A322803 Number of compositions (ordered partitions) of n into centered heptagonal numbers (A069099). 3
1, 1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 14, 18, 23, 29, 36, 45, 55, 67, 82, 101, 125, 155, 192, 239, 297, 368, 455, 562, 694, 857, 1058, 1308, 1619, 2005, 2483, 3074, 3805, 4708, 5822, 7198, 8900, 11007, 13616, 16846, 20845, 25795, 31918, 39489 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,9

LINKS

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

Wikipedia, Centered heptagonal number

Index entries for sequences related to compositions

FORMULA

G.f.: 1/(1 - Sum_{k>=0} x^(7*k*(k+1)/2+1)).

MAPLE

h:= proc(n) option remember; `if`(n<1, 0, (t->

      `if`((7*(t-1)*t+2)/2>n, t-1, t))(1+h(n-1)))

    end:

a:= proc(n) option remember; `if`(n=0, 1,

      add(a(n-(7*(i-1)*i+2)/2), i=1..h(n)))

    end:

seq(a(n), n=0..60);  # Alois P. Heinz, Dec 28 2018

MATHEMATICA

nmax = 54; CoefficientList[Series[1/(1 - Sum[x^(7 k (k + 1)/2 + 1), {k, 0, nmax}]), {x, 0, nmax}], x]

CROSSREFS

Cf. A069099, A280863, A282502, A282504, A322799, A322801, A322802.

Sequence in context: A291146 A023358 A322855 * A322800 A061379 A107322

Adjacent sequences:  A322800 A322801 A322802 * A322804 A322805 A322806

KEYWORD

nonn

AUTHOR

Ilya Gutkovskiy, Dec 26 2018

STATUS

approved

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Last modified August 5 07:29 EDT 2020. Contains 336209 sequences. (Running on oeis4.)