Second (lower) diagonal of partition triangle A047812.

Terms

a(0) =0a(1) =1a(2) =5a(3) =20a(4) =51a(5) =112a(6) =221a(7) =411a(8) =720a(9) =1221a(10) =2003a(11) =3206a(12) =5021a(13) =7728a(14) =11698a(15) =17472a(16) =25766a(17) =37580a(18) =54254a(19) =77617a(20) =110087a(21) =154942a(22) =216488a(23) =300456a(24) =414365a(25) =568113a(26) =774571a(27) =1050572a(28) =1417868a(29) =1904641