Closed 3-dimensional ball numbers (version 1): a(n)= number of integer points (i,j,k) contained in a closed ball of diameter n, centered at (0,0,0).

A053591

Closed 3-dimensional ball numbers (version 1): a(n)= number of integer points (i,j,k) contained in a closed ball of diameter n, centered at (0,0,0).

Terms

    a(0) =1a(1) =1a(2) =7a(3) =19a(4) =33a(5) =81a(6) =123a(7) =179a(8) =257a(9) =389a(10) =515a(11) =739a(12) =925a(13) =1189a(14) =1419a(15) =1791a(16) =2109a(17) =2553a(18) =3071a(19) =3695a(20) =4169a(21) =4945a(22) =5575a(23) =6403a(24) =7153a(25) =8217a(26) =9171a(27) =10395a(28) =11513a(29) =12893

External references