a(n) = A000041(n) * A000009(n).

Terms

a(0) =1a(1) =1a(2) =2a(3) =6a(4) =10a(5) =21a(6) =44a(7) =75a(8) =132a(9) =240a(10) =420a(11) =672a(12) =1155a(13) =1818a(14) =2970a(15) =4752a(16) =7392a(17) =11286a(18) =17710a(19) =26460a(20) =40128a(21) =60192a(22) =89178a(23) =130520a(24) =192150a(25) =278036a(26) =401940a(27) =577920a(28) =825396a(29) =1168640