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A322854
Number of compositions (ordered partitions) of n into hexagonal pyramidal numbers (A002412).
3
1, 1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 8, 10, 13, 17, 22, 28, 35, 43, 53, 67, 85, 108, 137, 173, 217, 271, 340, 428, 540, 682, 861, 1085, 1364, 1714, 2155, 2712, 3416, 4305, 5425, 6832, 8599, 10821, 13618, 17142, 21584, 27182, 34231, 43102, 54264, 68311, 85994
OFFSET
0,8
FORMULA
G.f.: 1/(1 - Sum_{k>=1} x^(k*(k+1)*(4*k-1)/6)).
MATHEMATICA
nmax = 53; CoefficientList[Series[1/(1 - Sum[x^(k (k + 1) (4 k - 1)/6), {k, 1, nmax}]), {x, 0, nmax}], x]
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Dec 29 2018
STATUS
approved