OFFSET
0,5
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
EXAMPLE
x - 1/3!*x^3 - 4/4!*x^4 - 3/5!*x^5 + 60/6!*x^6 ...
MATHEMATICA
Range[0, 30]! CoefficientList[Series[Tanh[Exp[x] - Sec[x]], {x, 0, 30}], x] (* Vincenzo Librandi, Aug 06 2018 *)
PROG
(Magma) m:=30; R<x>:=PowerSeriesRing(Rationals(), m); b:=Coefficients(R!(1+Tanh(Exp(x) - Sec(x)))); [0] cat [Factorial(n-1)*b[n]: n in [2..m]]; // Vincenzo Librandi, Aug 06 2018
(PARI) x = 'x + O('x^30); concat(0, Vec(serlaplace(tanh(exp(x) - 1/cos(x))))) \\ Michel Marcus, Aug 06 2018
CROSSREFS
KEYWORD
sign
AUTHOR
Patrick Demichel (patrick.demichel(AT)hp.com)
EXTENSIONS
a(0)=0 inserted and title improved by Sean A. Irvine, Aug 05 2018
STATUS
approved