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A360788
Expansion of Sum_{k>=0} x^k / (1 - (k*x)^3)^(k+1).
4
1, 1, 1, 1, 3, 25, 109, 324, 1135, 8803, 64189, 337854, 1707319, 13421410, 121248893, 894378619, 6082868725, 53046554917, 543432115477, 4989423130739, 42565774604131, 421544374075072, 4781440892689533, 51342685464272591, 522295380717090265
OFFSET
0,5
FORMULA
a(n) = Sum_{k=0..floor(n/3)} (n-3*k)^(3*k) * binomial(n-2*k,k).
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(sum(k=0, N, x^k/(1-(k*x)^3)^(k+1)))
(PARI) a(n) = sum(k=0, n\3, (n-3*k)^(3*k)*binomial(n-2*k, k));
CROSSREFS
Cf. A360783.
Sequence in context: A212054 A180324 A124245 * A373682 A166899 A201534
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Feb 20 2023
STATUS
approved