Number of partitions of n*(n-1)/2 into at most four parts.

Terms

a(0) =1a(1) =1a(2) =3a(3) =9a(4) =23a(5) =54a(6) =120a(7) =249a(8) =478a(9) =864a(10) =1495a(11) =2484a(12) =3969a(13) =6136a(14) =9234a(15) =13561a(16) =19464a(17) =27378a(18) =37845a(19) =51488a(20) =69012a(21) =91260a(22) =119239a(23) =154078a(24) =197026a(25) =249535a(26) =313290a(27) =390144a(28) =482120a(29) =591519