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%I #9 Oct 21 2019 02:10:32
%S 1,14,115,660,3805,20520,109779,551774,2921313,14482320,71576096,
%T 349292330,1804636693,8745745676,42107640345,203559063050,
%U 1040682784201,5002217935308,23823427871991,114772726273528,583453635620973,2795288971320092,13246283464422706,63736681240596050
%N a(n) = Sum_{k=0..n-3} T(n,k) * T(n,k+3), with T given by A026681.
%K nonn
%O 3,2
%A _Clark Kimberling_
%E More terms from _Sean A. Irvine_, Oct 21 2019