A009178 - OEIS

%I #18 Jun 21 2015 21:52:08

%S 1,0,2,-3,19,-90,556,-3885,31109,-279972,2799766,-30797415,369569047,

%T -4804397598,67261566464,-1008923496945,16142775951241,

%U -274427191171080,4939689441079594,-93854099380512267,1877081987610245531

%N Expansion of cosh(x)*cosh(log(1+x)).

%F a(n) ~ n! * (-1)^n * (exp(-1) + exp(1))/4. - _Vaclav Kotesovec_, Jan 22 2015

%t With[{nn=20},CoefficientList[Series[Cosh[x]Cosh[Log[1+x]],{x,0,nn}], x]Range[0,nn]!] (* _Harvey P. Dale_, Feb 02 2012 *)

%K sign,easy

%O 0,3

%A _R. H. Hardin_

%E Extended with signs by _Olivier Gérard_, Mar 15 1997