A186250 - OEIS

%I #11 Aug 20 2012 11:58:00

%S 1,-1,11,-256,10541,-672136,61001951,-7445096296,1172998147241,

%T -231333927486736,55747918840676411,-16100914826854576456,

%U 5485174647349481371661,-2175023364205612725532456,992565740287786208277022391,-516241740263310751317668520736

%N 2n-th derivative of sech(x)^sech(x) at x=0.

%C sech(x) = 1/cosh(x).

%C The sequence gives only 2n-th derivatives because (2n+1)-th derivatives are 0.

%t f[x_] := Sech[x]^Sech[x]; Table[Derivative[2*n] [f][0],{n,0,18}]

%Y Cf. A186249.

%K sign

%O 0,3

%A _Michel Lagneau_, Aug 18 2012