Number of -n..n arrays of 5 elements with first and second differences also in -n..n.

Terms

a(0) =47a(1) =537a(2) =2771a(3) =9593a(4) =25935a(5) =59533a(6) =121371a(7) =226521a(8) =394443a(9) =649989a(10) =1023515a(11) =1552101a(12) =2279419a(13) =3257221a(14) =4544919a(15) =6211381a(16) =8334179a(17) =11001745a(18) =14312231a(19) =18376077a(20) =23314439a(21) =29262209a(22) =36365967a(23) =44787505a(24) =54701247a(25) =66298329a(26) =79783443a(27) =95379513a(28) =113323919a(29) =133873821