OFFSET
0,4
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..100
FORMULA
E.G.F. = sec(exp(z)-1)
a(n) ~ 2*n!/((2+Pi)*log((2+Pi)/2)^(n+1)). - Vaclav Kotesovec, Sep 25 2013
MATHEMATICA
Table[D[Sec[Exp[x] - 1], {x, n}] /. x -> 0, {n, 0, 30}]
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Richard Chapling (r.chappers(AT)gmail.com), Jun 05 2008
EXTENSIONS
Typo in Mathematica program corrected by Vincenzo Librandi, Sep 26 2013
STATUS
approved