a(n) = (5/128)*n^4*(n mod 2) + (((-5/128)*n^4*(n mod 2) - 26) mod n) + n^3 (n > 0).

Terms

a(0) =2a(1) =8a(2) =31a(3) =66a(4) =154a(5) =220a(6) =443a(7) =518a(8) =991a(9) =1004a(10) =1910a(11) =1738a(12) =3315a(13) =2746a(14) =5359a(15) =4102a(16) =8185a(17) =5842a(18) =11963a(19) =8014a(20) =16858a(21) =10666a(22) =23112a(23) =13846a(24) =30899a(25) =17576a(26) =40447a(27) =21954a(28) =52029a(29) =27004