Number of points in Z^n of norm <= 7.

Terms

a(0) =1a(1) =15a(2) =149a(3) =1419a(4) =11833a(5) =89527a(6) =622573a(7) =4031123a(8) =24499121a(9) =140246303a(10) =759891589a(11) =3936654683a(12) =19595418729a(13) =94005744199a(14) =435555727453