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A360815
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Expansion of Sum_{k>=0} x^(3*k) / (1 - k*x)^(k+1).
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1
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1, 0, 0, 1, 2, 3, 5, 11, 30, 88, 260, 771, 2343, 7474, 25380, 91650, 347988, 1371873, 5570173, 23233703, 99676434, 440931977, 2014619700, 9506385864, 46246356169, 231348803925, 1187212953132, 6239006165820, 33546182775824, 184497923546700
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OFFSET
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0,5
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LINKS
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FORMULA
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a(n) = Sum_{k=0..floor(n/3)} k^(n-3*k) * binomial(n-2*k,k).
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PROG
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(PARI) my(N=30, x='x+O('x^N)); Vec(sum(k=0, N, x^(3*k)/(1-k*x)^(k+1)))
(PARI) a(n) = sum(k=0, n\3, k^(n-3*k)*binomial(n-2*k, k));
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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