a(n) = T(n,n-4), array T as in A055807.

Terms

a(0) =1a(1) =15a(2) =32a(3) =56a(4) =88a(5) =129a(6) =180a(7) =242a(8) =316a(9) =403a(10) =504a(11) =620a(12) =752a(13) =901a(14) =1068a(15) =1254a(16) =1460a(17) =1687a(18) =1936a(19) =2208a(20) =2504a(21) =2825a(22) =3172a(23) =3546a(24) =3948a(25) =4379a(26) =4840a(27) =5332a(28) =5856a(29) =6413