A394302 a(n) is the number of unit squares in the square lattice, divided by 4, that have 2 vertices strictly inside and 2 vertices strictly outside the circle (x-1/2)^2 + (y-1/2)^2 = n, i.e., the circle centered at the deep hole.

0, 1, 1, 1, 1, 3, 3, 1, 1, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 5, 5, 3, 3, 3, 3, 5, 5, 5, 5, 5, 5, 3, 3, 5, 5, 5, 5, 5, 5, 5, 5, 7, 7, 5, 5, 5, 5, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 5, 5, 5, 5, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 9, 9, 9, 9, 9, 9, 7, 7, 7, 7, 7, 7, 7, 7, 9

Offset

0,6

Links

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

Crossrefs

Cf. A000194, A005883, A393564.

Sequence in context: A338696 A301303 A285116 * A356301 A349813 A266529

Adjacent sequences: A394299 A394300 A394301 * A394303 A394304 A394305

Keyword

nonn

Author

Hugo Pfoertner, Mar 15 2026

Status

approved