A237708 Number of unit cubes, aligned with a three-dimensional Cartesian mesh, partially encircled along the edge of the first octant of a sphere centered at the origin, ordered by increasing radius.

0, 1, 1, 4, 4, 7, 6, 7, 7, 10, 10, 16, 13, 16, 16, 19, 16, 22, 22, 28, 25, 28, 27, 28, 28, 34, 28, 34, 34, 37, 34, 43, 40, 46, 43, 46, 46, 52, 46, 52, 49, 52, 49, 52, 52, 61, 55, 67, 63

Offset

0,4

Links

Table of n, a(n) for n=0..48.

Example

At radius 0, there are no partially filled cubes.  At radius >0 but < sqrt(1), there is 1 partially filled square along the edge of the sphere.  At radius = sqrt(1), there is 1 partially filled cube along the edge of the sphere.  At radius > 1 but < sqrt(2), there  are 4 partially filled cubes.

Crossrefs

Cf. A000378 (corresponds to the square radius of alternate entries).

Cf. A234300 (2-dimensional analog).

Sequence in context: A271781 A243454 A204008 * A342819 A016711 A023404

Adjacent sequences: A237705 A237706 A237707 * A237709 A237710 A237711

Keyword

nonn

Author

Rajan Murthy, Feb 11 2014

Status

approved