%I #9 Dec 29 2023 23:15:49
%S 2,7,20,56,155,429,1188,3298,9181,25634,71781,201569,567538,1601971,
%T 4532460,12851882,36516613,103955432,296471643,846932919,2423256440,
%U 6943726380,19924638557,57247669927,164688166948,474323305547
%N a(n) = A027113(n, 2n-2).
%Y Cf. A027113.
%K nonn
%O 2,1
%A _Clark Kimberling_