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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, 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
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
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