Number of points in N^n of norm <= 8.

Terms

a(0) =1a(1) =9a(2) =58a(3) =344a(4) =1867a(5) =9389a(6) =43774a(7) =191433a(8) =793049a(9) =3134307a(10) =11887373a(11) =43482354a(12) =154000286a(13) =529571812a(14) =1771709727a(15) =5775999764a(16) =18376959165a(17) =57141981155a(18) =173888869424a(19) =518545311255