A012947 sech(tan(x)+sin(x))=1-4/2!*x^2+72/4!*x^4-3318/6!*x^6+283640/8!*x^8...

1, -4, 72, -3318, 283640, -38913946, 7833273228, -2173778522118, 795497453081936, -371167668444757618, 215062106038617789684, -151501184773295673275454, 127516166752654555516090424

Offset

0,2

Links

Table of n, a(n) for n=0..12.

Mathematica

With[{nn=30}, Take[CoefficientList[Series[Sech[Tan[x]+Sin[x]], {x, 0, nn}], x] Range[0, nn]!, {1, -1, 2}]] (* Harvey P. Dale, Oct 29 2014 *)

Crossrefs

Sequence in context: A266865 A327882 A003718 * A203535 A013066 A013102

Adjacent sequences: A012944 A012945 A012946 * A012948 A012949 A012950

Keyword

sign

Author

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

Status

approved