Row sums of Riordan array (c(-x^2),xc(-x^2)^2)^(-1) where c(x) is the g.f. of A000108.

Terms

a(0) =1a(1) =1a(2) =2a(3) =4a(4) =9a(5) =20a(6) =47a(7) =109a(8) =262a(9) =622a(10) =1516a(11) =3653a(12) =8988a(13) =21883a(14) =54213a(15) =133004a(16) =331233a(17) =817432a(18) =2044151a(19) =5068346a(20) =12716872a(21) =31651555a(22) =79636493a(23) =198843284a(24) =501466519a(25) =1255489165a(26) =3172569392a(27) =7961388439a(28) =20152910577a(29) =50674576772