A071611 Number of points (i,j,k) on the surface of a sphere around (0,0,0) with squared radius A071609(n).

6, 12, 24, 30, 48, 72, 96, 120, 144, 168, 192, 240, 264, 312, 336, 384, 408, 432, 480, 504, 528, 552, 576, 600, 672, 696, 720, 768, 816, 864, 936, 1008, 1032, 1056, 1104, 1200, 1248, 1296, 1344, 1440, 1512, 1584, 1680, 1704, 1752, 1848, 1920, 2016

Offset: 1

Author

Hugo Pfoertner, May 25 2002

Keywords

• nonn

Comments

a(n) is the number of lattice points on a sphere around (0,0,0) with r^2 = A071609(n).

Examples

			A sphere with radius 1 has 6 lattice points on its surface, so a(1)=6. A sphere with r=sqrt(2) passes through 12 lattice points of the shape (1,1,0), so a(2)=12. A sphere with r=sqrt(5) passes through 24 lattice points with shape (2,1,0), so a(3)=24. A sphere with r=sqrt(9) passes through 6 lattice points of shape (3,0,0) and through 24 lattice points of shape (2,2,1), so a(4)=6+24=30.
		

Links

• Hugo Pfoertner, Table of n, a(n) for n = 1..189

Crossrefs

Cf. A005875, A071342-A071344, A071609, A071610.

Formula

a(n) = A005875(A071609(n)). - Daniel Suteu, Aug 13 2021