OFFSET
0,5
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
MATHEMATICA
Range[0, 20]! CoefficientList[ Series[ Sech[ArcTan[x] Log[x + 1]], {x, 0, 20}], x] (* Robert G. Wilson v, Nov 13 2011 *)
CROSSREFS
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
STATUS
approved