OFFSET
0,3
COMMENTS
sech(x) = 1/cosh(x).
The sequence gives only 2n-th derivatives because (2n+1)-th derivatives are 0.
MATHEMATICA
f[x_] := Sech[x]^Sech[x]; Table[Derivative[2*n] [f][0], {n, 0, 18}]
CROSSREFS
KEYWORD
sign
AUTHOR
Michel Lagneau, Aug 18 2012
STATUS
approved