-1 + number of partitions of n.

Terms

a(0) =0a(1) =0a(2) =1a(3) =2a(4) =4a(5) =6a(6) =10a(7) =14a(8) =21a(9) =29a(10) =41a(11) =55a(12) =76a(13) =100a(14) =134a(15) =175a(16) =230a(17) =296a(18) =384a(19) =489a(20) =626a(21) =791a(22) =1001a(23) =1254a(24) =1574a(25) =1957a(26) =2435a(27) =3009a(28) =3717a(29) =4564