A377743 E.g.f. satisfies A(x) = exp(x) / (1 - x * A(x))^3.
1, 4, 43, 853, 25141, 989581, 48885187, 2910389875, 202958554057, 16233163690537, 1465257396236551, 147359765665925143, 16341437664329027389, 1981169884084699982701, 260701144663332062732491, 37007345616327485166160651, 5637148375602304430334748945, 917186940500490837457393476817
Offset: 0
Keywords
Programs
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PARI
a(n) = n!*sum(k=0, n, (k+1)^(n-k-1)*binomial(4*k+2, k)/(n-k)!);
Formula
a(n) = n! * Sum_{k=0..n} (k+1)^(n-k-1) * binomial(4*k+2,k)/(n-k)!.