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A322853
Number of compositions (ordered partitions) of n into pentagonal pyramidal numbers (A002411).
3
1, 1, 1, 1, 1, 1, 2, 3, 4, 5, 6, 7, 9, 12, 16, 21, 27, 34, 44, 57, 74, 96, 124, 159, 205, 265, 343, 444, 574, 740, 954, 1231, 1590, 2055, 2656, 3430, 4428, 5716, 7380, 9531, 12312, 15902, 20536, 26518, 34242, 44218, 57106, 73751, 95245, 122999, 158837, 205117
OFFSET
0,7
FORMULA
G.f.: 1/(1 - Sum_{k>=1} x^(k^2*(k+1)/2)).
MATHEMATICA
nmax = 51; CoefficientList[Series[1/(1 - Sum[x^(k^2 (k + 1)/2), {k, 1, nmax}]), {x, 0, nmax}], x]
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Dec 29 2018
STATUS
approved