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A078184
Number of solutions to n^2 < x^2 + y^2 + z^2 < (n+1)^2; number of lattice points between spheres of radii n and n+1.
0
0, 20, 60, 128, 228, 380, 440, 684, 860, 1068, 1328, 1548, 1940, 2288, 2484, 2924, 3300, 3824, 4140, 4700, 5240, 5484, 6260, 6864, 7340, 8180, 8676, 9392, 9804, 10988, 11208, 12572, 13100, 13860, 14792, 15588, 16604, 17328, 18500, 19292
OFFSET
0,2
FORMULA
a(n) = A078183(n+1) - A000605(n)
MATHEMATICA
Table[Sum[SquaresR[3, k], {k, n^2 + 1, (n + 1)^2 - 1}], {n, 0, 50}]
CROSSREFS
Sequence in context: A344200 A163761 A154072 * A362268 A116530 A219830
KEYWORD
nonn
AUTHOR
T. D. Noe, Nov 21 2002
STATUS
approved