A013501 Expansion of e.g.f.: exp(sec(x)-exp(x))=1-x+1/2!*x^2-2/3!*x^3+9/4!*x^4-32/5!*x^5...

1, -1, 1, -2, 9, -32, 157, -828, 5481, -35496, 290649, -2290840, 22092829, -204459452, 2273871485, -24119527604, 303515669169, -3629239434576, 50931449481777, -677485393669744, 10484228007290613, -153504673218503140, 2595681901243781013, -41471161060916985516, 760471144497476539177, -13162910847523759863288

Offset

0,4

Links

Table of n, a(n) for n=0..25.

Maple

read transforms;
t1:=exp(sec(x)-exp(x)); #A013501
t2:=series(t1, x, 30);
t3:=SERIESTOLISTMULT(%);

Mathematica

With[{nn=30}, CoefficientList[Series[Exp[Sec[x]-Exp[x]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Dec 14 2016 *)

Crossrefs

Sequence in context: A150918 A150919 A150920 * A179230 A114853 A331727

Adjacent sequences: A013498 A013499 A013500 * A013502 A013503 A013504

Keyword

sign

Author

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

Extensions

More terms from N. J. A. Sloane, Dec 17 2011

Definition clarified by Harvey P. Dale, Dec 14 2016

Status

approved