%I #8 May 10 2021 21:03:39
%S 1,2,3,5,9,18,28,53,101,195,390,704,1371,2676,5253,10506,19840,39056,
%T 76968,152168,304336,586864,1161577,2300544,4565558,9131116,17813324,
%U 35369544,70256203,139745471,279490942,549138068,1092533184
%N a(n) = Sum_{i=0..n} T(i,n-i) where T is given by A047020.
%K nonn
%O 0,2
%A _Clark Kimberling_
%E a(26) corrected by _Sean A. Irvine_, May 10 2021