|
| |
|
|
A014203
|
|
Sum {i^2+j^2+k^2}, i^2+j^2+k^2 <= n.
|
|
0
| |
|
|
0, 6, 30, 54, 78, 198, 342, 342, 438, 708, 948, 1212, 1308, 1620, 2292, 2292, 2388, 3204, 3852, 4308, 4788, 5796, 6324, 6324, 6900, 7650, 9522, 10386, 10386, 12474, 13914, 13914, 14298, 15882, 17514, 19194, 20274, 21162, 23898, 23898, 24858
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 0,2
|
|
|
REFERENCES
| J. H. Conway and N. J. A. Sloane, "Sphere Packings, Lattices and Groups", Springer-Verlag, p. 107.
|
|
|
EXAMPLE
| Take n=3 say. The sum contains the terms 0 (once) from (0,0,0); 1 (6 times) from (+-1,0,0); 2 (12 times) from (+-1, +-1, 0); and 3 (8 times) from (+-1, +-1, +-1); for a total of 0+6+24+24=54.
|
|
|
CROSSREFS
| Sequence in context: A100194 A070195 A110175 * A044083 A024406 A024365
Adjacent sequences: A014200 A014201 A014202 * A014204 A014205 A014206
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| E.V. Flynn (evflynn(AT)liverpool.ac.uk)
|
|
|
EXTENSIONS
| More terms from James A. Sellers (sellersj(AT)math.psu.edu), Feb 05 2000
|
| |
|
|
