A009428 Expansion of e.g.f. log(1+x)/cos(tanh(x)).

0, 1, -1, 5, -12, 29, -165, 993, -7056, 62649, -540225, 5044445, -56372844, 685980437, -8868937077, 124034330553, -1855540686720, 29570974192753, -502444027531233, 9041323571823925, -171561171727515820, 3427632445624110605

Offset: 0

Author

R. H. Hardin

Keywords

• sign
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..200

Programs

Mathematica

With[{nn=30},CoefficientList[Series[Log[1+x]/Cos[Tanh[x]],{x,0,nn}], x]Range[0,nn]!] (* Harvey P. Dale, Oct 06 2011 *)

Extensions

Extended with signs by Olivier Gérard, Mar 15 1997

Corrected Mathematica program, Harvey P. Dale, Oct 06 2011