Number of second differences of arrays of length 6 of numbers in 0..n.

Terms

a(0) =63a(1) =665a(2) =3151a(3) =9705a(4) =23351a(5) =47953a(6) =88215a(7) =149681a(8) =238735a(9) =362601a(10) =529343a(11) =747865a(12) =1027911a(13) =1380065a(14) =1815751a(15) =2347233a(16) =2987615a(17) =3750841a(18) =4651695a(19) =5705801a(20) =6929623a(21) =8340465a(22) =9956471a(23) =11796625a(24) =13880751a(25) =16229513a(26) =18864415a(27) =21807801a(28) =25082855