Number of 8-element subsets of [n] whose sum is a triangular number.

Terms

a(0) =1a(1) =1a(2) =5a(3) =17a(4) =48a(5) =122a(6) =276a(7) =573a(8) =1112a(9) =2042a(10) =3578a(11) =6024a(12) =9803a(13) =15476a(14) =23793a(15) =35728a(16) =52522a(17) =75761a(18) =107416a(19) =149923a(20) =206288a(21) =280145a(22) =375868a(23) =498713a(24) =654914a(25) =851807a(26) =1098032a(27) =1403673a(28) =1780402a(29) =2241738