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

Terms

a(0) =1a(1) =1a(2) =3a(3) =7a(4) =14a(5) =27a(6) =48a(7) =80a(8) =127a(9) =192a(10) =280a(11) =397a(12) =547a(13) =736a(14) =972a(15) =1261a(16) =1610a(17) =2028a(18) =2523a(19) =3104a(20) =3781a(21) =4563a(22) =5461a(23) =6487a(24) =7651a(25) =8965a(26) =10443a(27) =12097a(28) =13940a(29) =15987