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A012419
Expansion of e.g.f.: sech(arctan(x)*exp(x))=1-1/2!*x^2-6/3!*x^3-11/4!*x^4+100/5!*x^5...
0
1, 0, -1, -6, -11, 100, 995, 2030, -45943, -568632, -1189145, 54818082, 845395901, 1936128428, -142744278261, -2685086733290, -6197620433007, 713212265955216, 15393015776009807, 26780979282600266
OFFSET
0,4
MATHEMATICA
With[{nn=20}, CoefficientList[Series[Sech[ArcTan[x]Exp[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Mar 06 2016 *)
CROSSREFS
Sequence in context: A192893 A188599 A217934 * A012663 A180929 A212592
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
Definition (Name) clarified by Harvey P. Dale, Mar 06 2016
STATUS
approved