A193468 - OEIS

%I #9 Nov 05 2024 18:59:10

%S 1,1,3,21,193,2125,32281,655235,15530705,427214889,14127457681,

%T 542796582295,23400843532969,1140401734145453,62743287535847465,

%U 3822548966261363595,256275705820386124321,18923726002188870476497

%N a(n) = A193466(n)/n for n>=1.

%C A193466 is defined by the e.g.f.: Sum_{n>=0} x^n * Product_{k=1..n} cosh(k*x).

%o (PARI) {a(n)=local(X=x+x*O(x^n), Egf); Egf=sum(m=0, n, x^m*prod(k=1, m, cosh(k*X))); if(n<1,0,(n-1)!*polcoeff(Egf, n))}

%Y Cf. A193467.

%K nonn

%O 1,3

%A _Paul D. Hanna_, Jul 27 2011