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

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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 *)