A012620 - OEIS

%I #4 Feb 24 2012 12:51:03

%S 1,0,12,120,15120,640320,143136576,14091272832,5105629251840,

%T 906008454739968,490783256100396032,136461255865204086784,

%U 104233836908816608661504,41544908070600747941806080

%N sec(arcsinh(x)*tan(x))=1+12/4!*x^4+120/6!*x^6+15120/8!*x^8...

%K nonn

%O 0,3

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