A sequence derived from a Ferrers graph partition of 16.

Terms

a(0) =1a(1) =5a(2) =16a(3) =60a(4) =213a(5) =771a(6) =2772a(7) =9990a(8) =35973a(9) =129573a(10) =466668a(11) =1680804a(12) =6053697a(13) =21803499a(14) =78529176a(15) =282836934a(16) =1018687833a(17) =3668986773a(18) =13214513016a(19) =47594435868a(20) =171419886333a(21) =617399427555