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A187920 Triangle T(n,k) for A(x)^k=sum(n>=k T(n,k)*x^n), where o.g.f. A(x) satisfies A(x)=(1+x*A(x)^3)/(1-x*A(x)^3), 0
1, 2, 1, 14, 4, 1, 134, 32, 6, 1, 1482, 324, 54, 8, 1, 17818, 3696, 578, 80, 10, 1, 226214, 45316, 6810, 904, 110, 12, 1, 2984206, 583152, 85278, 11008, 1310, 144, 14, 1, 40503890, 7769348, 1113854, 140936, 16490, 1804, 182, 16, 1, 561957362, 106250144, 15004746, 1870352, 216002, 23472, 2394, 224, 18, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,2
LINKS
Vladimir Kruchinin and D. V. Kruchinin, Composita and their properties, arXiv:1103.2582 [math.CO], 2011-2013.
FORMULA
T(n,k):=k/(3*n-2*k)*sum(i=0..n-k, binomial(3*n-2*k,n-k-i)*binomial(3*n-2*k+i-1,3*n-2*k-1)), n>=k>0.
PROG
(Maxima)
T(n, k):=k/(3*n-2*k)*sum(binomial(3*n-2*k, n-k-i)*binomial(3*n-2*k+i-1, 3*n-2*k-1), i, 0, n-k);
CROSSREFS
Sequence in context: A217475 A288298 A288762 * A307804 A338207 A063613
KEYWORD
nonn,tabl
AUTHOR
Vladimir Kruchinin, Mar 16 2011
STATUS
approved

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Last modified March 28 04:13 EDT 2024. Contains 371235 sequences. (Running on oeis4.)