Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.
%I #7 Jul 30 2019 19:27:40
%S 1,1,4,4,4,20,36,52,132,292,580,1252,2628,6772,14820,32404,75012,
%T 183108,423428,953924,2225028,5435604,12770340,29545076,69900164,
%U 170528612,405553988,954683428,2267938244,5585542964,13382224612,31793247188
%N a(n) = Sum_{i=1..floor((n+2)/4)} a(2i-1)*a(n-2i+1), with a(1)=a(2)=1 and a(3)=4.
%K nonn
%O 1,3
%A _Clark Kimberling_
%E Offset corrected and title improved by _Sean A. Irvine_, Jul 30 2019