A394304 a(n) is the number of unit cubes in the cubic lattice, divided by 8, that have 7 vertices strictly inside and 1 vertex strictly outside the sphere (x-1/2)^2 + (y-1/2)^2 + (z-1/2)^2 = n, i.e., the sphere centered at the deep hole.

0, 0, 0, 0, 0, 1, 1, 0, 0, 3, 3, 0, 0, 3, 3, 4, 4, 1, 1, 6, 6, 3, 3, 6, 6, 3, 3, 9, 9, 6, 6, 4, 4, 10, 10, 7, 7, 12, 12, 6, 6, 9, 9, 12, 12, 12, 12, 9, 9, 12, 12, 15, 15, 13, 13, 13, 13, 13, 13, 16, 16, 12, 12, 21, 21, 18, 18, 15, 15, 18, 18, 15, 15, 21, 21, 18, 18, 21

Offset

0,10

Links

Hugo Pfoertner, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A005878, A393827, A394294, A394295, A394296, A394297, A394305, A394306.

Sequence in context: A109247 A021307 A170852 * A245320 A330341 A152893

Adjacent sequences: A394301 A394302 A394303 * A394305 A394306 A394307

Keyword

nonn

Author

Hugo Pfoertner, Mar 15 2026

Status

approved