A013566 Expansion of e.g.f. sec(log(x+1)/exp(x)).

1, 0, 1, -9, 64, -510, 5140, -62650, 868516, -13417104, 229831820, -4334605748, 89205406112, -1988081805528, 47701228486496, -1226141059648440, 33617215231898512, -979251053876769920, 30201854389236416848

Offset

0,4

Links

G. C. Greubel, Table of n, a(n) for n = 0..400

Formula

E.g.f.: sec(log(x+1)/exp(x)).

Example

sec(log(x+1)/exp(x)) = 1 + 1/2!*x^2 - 9/3!*x^3 + 64/4!*x^4 - 510/5!*x^5 + ..

Mathematica

CoefficientList[Series[Sec[Log[x + 1]/Exp[x]], {x, 0, 40}], x] Range[0, 40]! (* G. C. Greubel, Nov 15 2016 *)

Prog

(PARI) for(n=0, 15, print1(n!*polcoeff(1/cosh(ln(1+x)*exp(-x)), n), ", ")) \\ G. C. Greubel, Nov 16 2016

Crossrefs

Sequence in context: A049684 A037540 A037484 * A056769 A273232 A064546

Adjacent sequences: A013563 A013564 A013565 * A013567 A013568 A013569

Keyword

sign

Author

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

Status

approved