A381140 Expansion of e.g.f. exp( -LambertW(-x * cosh(x)) ).
1, 1, 3, 19, 161, 1781, 24667, 409991, 7959233, 176920489, 4432942931, 123648692795, 3800647961761, 127654261471517, 4651982506605995, 182824074836850991, 7708128977570816129, 347059689259637711441, 16621016953663100702755, 843658152872351669816675
Offset: 0
Keywords
Links
- Eric Weisstein's World of Mathematics, Lambert W-Function.
Programs
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PARI
a185951(n, k) = binomial(n, k)/2^k*sum(j=0, k, (2*j-k)^(n-k)*binomial(k, j)); a(n) = sum(k=0, n, (k+1)^(k-1)*a185951(n, k));
Formula
E.g.f. A(x) satisfies A(x) = exp( x * cosh(x) * A(x) ).
a(n) = Sum_{k=0..n} (k+1)^(k-1) * A185951(n,k).
Comments