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).

1, 1, 7, 19, 33, 81, 123, 179, 257, 389, 515, 739, 925, 1189, 1419, 1791, 2109, 2553, 3071, 3695, 4169, 4945, 5575, 6403, 7153, 8217, 9171, 10395, 11513, 12893, 14147, 15515, 17077, 18853, 20479, 22575, 24405, 26745, 28671, 31103, 33401

Offset

0,3

Comments

a(n)/(n/2)^3->4/3*Pi

Links

Table of n, a(n) for n=0..40.

Crossrefs

Sequence in context: A038869 A147503 A147465 * A165333 A154878 A124270

Adjacent sequences: A053588 A053589 A053590 * A053592 A053593 A053594

Keyword

easy,nonn

Author

Klaus Strassburger (strass(AT)ddfi.uni-duesseldorf.de), Jan 19 2000

Status

approved