A365034 E.g.f. satisfies A(x) = exp(x * A(x)^2 * (1 + x * A(x))^3).
1, 1, 11, 175, 4317, 142561, 5929513, 297901899, 17557448681, 1188110627137, 90804918357261, 7737033497254579, 727253150819898541, 74760871323339663489, 8344094871249960257009, 1004872166403751985971291, 129883465213311163328142417
Offset: 0
Keywords
Programs
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PARI
a(n) = n!*sum(k=0, n, (n+k+1)^(k-1)*binomial(3*k, n-k)/k!);
Formula
a(n) = n! * Sum_{k=0..n} (n+k+1)^(k-1) * binomial(3*k,n-k)/k!.