OFFSET
0,4
COMMENTS
a(39) is negative. - Vaclav Kotesovec, Aug 17 2022
LINKS
Seiichi Manyama, Table of n, a(n) for n = 0..486
FORMULA
a(0) = 1; a(n) = Sum_{k=1..n} A354520(k) * binomial(n-1,k-1) * a(n-k).
MATHEMATICA
With[{nn=30}, CoefficientList[Series[Cosh[x]^Exp[x], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Jul 05 2026 *)
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serlaplace(cosh(x)^exp(x)))
(PARI) a354520(n) = sum(k=1, n\2, (16^k-4^k)*bernfrac(2*k)/(2*k)*binomial(n, 2*k));
a_vector(n) = my(v=vector(n+1)); v[1]=1; for(i=1, n, v[i+1]=sum(j=1, i, a354520(j)*binomial(i-1, j-1)*v[i-j+1])); v;
CROSSREFS
KEYWORD
sign
AUTHOR
Seiichi Manyama, Aug 16 2022
STATUS
approved