a(n) = partitions(n)*partitions(n+1).

Terms

a(0) =1a(1) =2a(2) =6a(3) =15a(4) =35a(5) =77a(6) =165a(7) =330a(8) =660a(9) =1260a(10) =2352a(11) =4312a(12) =7777a(13) =13635a(14) =23760a(15) =40656a(16) =68607a(17) =114345a(18) =188650a(19) =307230a(20) =496584a(21) =793584a(22) =1257510a(23) =1976625a(24) =3083850a(25) =4769688a(26) =7332360a(27) =11191180a(28) =16972670a(29) =25582260