A013256 - OEIS

%I #6 Dec 19 2022 13:31:44

%S 1,0,0,0,3,-40,250,-840,5145,-117360,1667700,-15263600,150117275,

%T -2670166200,50627578950,-785508087000,12133753256625,

%U -237020801836000,5185811491549000,-108420617788236000

%N Expansion of e.g.f.: sec(log(x+1)-arctan(x))=1+3/4!*x^4-40/5!*x^5+250/6!*x^6-840/7!*x^7...

%t With[{nn=20},CoefficientList[Series[Sec[Log[x+1]-ArcTan[x]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Dec 19 2022 *)

%K sign

%O 0,5

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

%E Definition clarified by _Harvey P. Dale_, Dec 19 2022