a(n) = Sum_{j=0..n} A047072(j, n-j).

Terms

a(0) =1a(1) =2a(2) =4a(3) =4a(4) =8a(5) =12a(6) =24a(7) =40a(8) =80a(9) =140a(10) =280a(11) =504a(12) =1008a(13) =1848a(14) =3696a(15) =6864a(16) =13728a(17) =25740a(18) =51480a(19) =97240a(20) =194480a(21) =369512a(22) =739024a(23) =1410864a(24) =2821728a(25) =5408312a(26) =10816624a(27) =20801200a(28) =41602400a(29) =80233200