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A024957 a(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=2 and a(2)=a(3)=1. 0

%I

%S 2,1,1,2,4,9,20,44,97,230,540,1257,2920,7168,17393,41806,100408,

%T 250098,618124,1517008,3716627,9375710,23479016,58419236,145210076,

%U 368786352,931600246,2341625080,5877503872,15027036202,38225273720,96794415372

%N a(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=2 and a(2)=a(3)=1.

%K nonn

%O 1,1

%A _Clark Kimberling_

%E Offset corrected and title improved by _Sean A. Irvine_, Jul 30 2019

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Last modified October 30 02:32 EDT 2020. Contains 338076 sequences. (Running on oeis4.)