A027289 - OEIS

%I #8 Oct 26 2019 23:08:52

%S 1,3,18,55,264,847,3744,12465,52868,180895,749220,2617173,10680656,

%T 37915317,153240864,551019963,2212417314,8038946075,32129224712,

%U 117758845827,469105048654,1731917060158,6882935960496,25569740611270,101442831429264,378875492015643

%N a(n) = Sum_{k=0..floor(n/2)-1} T(n,k) * T(n,k+2), with T given by A026009.

%K nonn

%O 2,2

%A _Clark Kimberling_

%E More terms from _Sean A. Irvine_, Oct 26 2019