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%I #11 Dec 11 2019 21:46:20
%S 1,18,1752,282304,54547200,11478167040,2533556365312,576271774875648,
%T 133776598692003840,31513560479297044480,7505638177922587557888,
%U 1802924878727702252617728,436026430783762289982963712
%N Even-indexed members of A067302.
%F a(n) = A067302(2n) = (n+1)*A067297(2*n).
%F G.f.: (x*(d/dx)A(x) + A(x)) with A(x) g.f. of A067320.
%Y Cf. A067322 (odd-indexed members of A067302).
%K nonn,easy
%O 0,2
%A _Wolfdieter Lang_, Feb 05 2002