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A186250
2n-th derivative of sech(x)^sech(x) at x=0.
1
1, -1, 11, -256, 10541, -672136, 61001951, -7445096296, 1172998147241, -231333927486736, 55747918840676411, -16100914826854576456, 5485174647349481371661, -2175023364205612725532456, 992565740287786208277022391, -516241740263310751317668520736
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
Cf. A186249.
Sequence in context: A377426 A052782 A186249 * A324327 A142208 A168466
KEYWORD
sign
AUTHOR
Michel Lagneau, Aug 18 2012
STATUS
approved