Partial sums of A003149.

Terms

a(0) =1a(1) =3a(2) =8a(3) =24a(4) =88a(5) =400a(6) =2212a(7) =14500a(8) =110116a(9) =951076a(10) =9205156a(11) =98646436a(12) =1159016356a(13) =14808626596a(14) =204358994596