A381942 G.f. A(x) satisfies A(x) = (1 + x)^3 * B(x*A(x)), where B(x) is the g.f. of A002293.
1, 4, 14, 96, 905, 9550, 107552, 1265372, 15364920, 191090255, 2421646300, 31157939594, 405932855044, 5344301858465, 70990458721140, 950263442420120, 12805328720666376, 173574888045493536, 2365049262321662145, 32374714068988416170, 445017678283209218750, 6140131349497715896244
Offset: 0
Keywords
Programs
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PARI
a(n) = sum(k=0, n, binomial(5*k+1, k)*binomial(3*k+3, n-k)/(5*k+1));
Formula
a(n) = Sum_{k=0..n} binomial(5*k+1,k) * binomial(3*k+3,n-k)/(5*k+1).