A009237 Expansion of exp(tan(log(1+x))).

1, 1, 0, 2, -4, 26, -134, 930, -6728, 53056, -413744, 2752936, -3042040, -488089848, 16658828096, -442856699584, 11075864697536, -274957302952960, 6922538197811392, -178529204224920384, 4739350807332125056

Offset

0,4

Links

Table of n, a(n) for n=0..20.

Mathematica

With[{nn=30}, CoefficientList[Series[Exp[Tan[Log[1+x]]], {x, 0, nn}], x] Range[0, nn]!] (* Harvey P. Dale, Oct 26 2011 *)

Crossrefs

Sequence in context: A367428 A085700 A087404 * A019019 A215882 A032328

Adjacent sequences: A009234 A009235 A009236 * A009238 A009239 A009240

Keyword

sign,easy

Author

R. H. Hardin

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Status

approved