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%I #9 Jan 04 2025 14:52:47
%S 0,1,8,256,17408,1910656,309060608,69341479936,20585851486208,
%T 7805361597546496,3678560956503031808,2108887897093614862336,
%U 1444987869648059585527808,1166088560957891800314413056,1094603065624651626325011857408,1182521392128023075821382696697856
%N Expansion of tan(tan(x)^2)/2.
%F a(n) = A009710(n)/2. - _Alois P. Heinz_, Jan 04 2025
%t Tan[ Tan[ x ]^2 ]/2 (* Even Part *)
%Y Cf. A009710.
%K nonn
%O 0,3
%A _R. H. Hardin_