Number of second differences of arrays of length 7 of numbers in 0..n.

Terms

a(0) =127a(1) =2059a(2) =14053a(3) =58141a(4) =176851a(5) =439927a(6) =951049a(7) =1854553a(8) =3342151a(9) =5659651a(10) =9113677a(11) =14078389a(12) =21002203a(13) =30414511a(14) =42932401a(15) =59267377a(16) =80232079a(17) =106747003a(18) =139847221a(19) =180689101a(20) =230557027a(21) =290870119a(22) =363188953a(23) =449222281a(24) =550833751