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%I #6 Feb 05 2022 16:28:08
%S 0,1,12,175,2448,34481,485100,6826079,96049728,1351523425,19017374892,
%T 267594778639,3765344259600,52982414452241,745519146496332,
%U 10490250465629375,147609025664755968,2077016609773544641,29225841562491165900,411238798484657629039
%N a(n) = Pell(n)*Pell(2*n)/2.
%F G.f.: (x^3+x)/((1+2x-x^2)*(1-14x-x^2)).
%t CoefficientList[Series[(x^3+x)/((1+2x-x^2)(1-14x-x^2)),{x,0,30}],x] (* _Harvey P. Dale_, Dec 20 2018 *)
%Y Cf. A000129.
%K nonn
%O 0,3
%A _Gary W. Adamson_, Feb 01 2000