Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).
%I #6 Nov 29 2018 15:27:26
%S 1,0,0,0,-12,60,-570,3780,-26880,145152,67800,-19702320,483806664,
%T -8808530016,143791860576,-2098017710880,26000312931840,
%U -200354333649536,-2365679417115840,173236427161446528
%N Expansion of e.g.f.: sech(tan(x)*log(x+1))=1-12/4!*x^4+60/5!*x^5-570/6!*x^6+3780/7!*x^7...
%t With[{nn=20},CoefficientList[Series[Sech[Tan[x]Log[x+1]],{x,0,nn}],x] Range[0,nn]!] (* _Harvey P. Dale_, Nov 29 2018 *)
%K sign
%O 0,5
%A Patrick Demichel (patrick.demichel(AT)hp.com)
%E Definition clarified by _Harvey P. Dale_, Nov 29 2018