A380044 E.g.f. A(x) satisfies A(x) = 1/sqrt( 1 - 2*x*exp(x)*A(x) ).
1, 1, 7, 81, 1393, 32025, 924831, 32208337, 1314511297, 61553580849, 3253663709335, 191661481308561, 12451241630689137, 884434637282286025, 68195094329460133231, 5672843158404577658385, 506413381554227338302721, 48290505275596520116029537, 4899034372132659112326787239
Offset: 0
Keywords
Programs
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PARI
a(n) = n!*sum(k=0, n, 2^k*k^(n-k)*binomial(3*k/2+1/2, k)/((3*k+1)*(n-k)!));
Formula
a(n) = n! * Sum_{k=0..n} 2^k * k^(n-k) * binomial(3*k/2+1/2,k)/( (3*k+1)*(n-k)! ).