A009371 - OEIS

%I #14 Jun 22 2015 22:22:44

%S 0,1,1,4,0,45,-155,1748,-13496,151169,-1682191,22018412,-307464872,

%T 4746159613,-78744546907,1410956472396,-27026759291728,

%U 552443153007777,-11988735452427903,275451486233018100,-6677966707663119664

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

%F a(n) ~ (n-1)! * (-1)^(n+1) * exp(-Pi/4) * (4/Pi)^n. - _Vaclav Kotesovec_, Jan 23 2015

%t Log[ 1+Tan[ x ] ]*Exp[ x ]

%t CoefficientList[Series[E^x*Log[1 + Tan[x]], {x, 0, 20}], x] * Range[0, 20]! (* _Vaclav Kotesovec_, Jan 23 2015 *)

%K sign,easy

%O 0,4

%A _R. H. Hardin_

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