Left diagonal of partition triangle A047812.

Terms

a(0) =0a(1) =1a(2) =3a(3) =5a(4) =9a(5) =13a(6) =20a(7) =28a(8) =40a(9) =54a(10) =75a(11) =99a(12) =133a(13) =174a(14) =229a(15) =295a(16) =383a(17) =488a(18) =625a(19) =790a(20) =1000a(21) =1253a(22) =1573a(23) =1956a(24) =2434a(25) =3008a(26) =3716a(27) =4563a(28) =5602a(29) =6840