A012647 - OEIS

%I #8 Nov 01 2013 05:35:25

%S 0,2,0,-80,-1344,14848,-478720,233089792,-40950956032,10897158856704,

%T -3658314845569024,1494490439452852224,-737151399778288664576,

%U 431277629004040408989696,-295401420454303808123568128

%N sin(arcsinh(x)*sinh(x))=2/2!*x^2-80/6!*x^6-1344/8!*x^8+14848/10!*x^10...

%F a(n) ~ (-1)^(n+1) * cos(sin(1)*Pi/2) * sin(1) * 2^(2*n) * n^(2*n-1) / exp(2*n). - _Vaclav Kotesovec_, Nov 01 2013

%t Table[n!*SeriesCoefficient[Sin[ArcSinh[x]*Sinh[x]],{x,0,n}],{n,0,40,2}] (* _Vaclav Kotesovec_, Nov 01 2013 *)

%K sign

%O 0,2

%A Patrick Demichel (patrick.demichel(AT)hp.com)

%E Prepended missing a(0)=0 from _Vaclav Kotesovec_, Nov 01 2013