0,2

See A255250 for a comment on Gauss's circle problem in an octant and a link.

Table of n, a(n) for n=0..60.

a(n) = sum((-1)^m*T(n, m), m=0..floor(n/sqrt(2))), n >= 0, with T(n, m) = A255250(n, m) = floor(sqrt(n^2 - m^2)) - (m-1).

Cf. A255250.

Sequence in context: A328804 A064514 A112342 * A063712 A340458 A185977

Adjacent sequences: A256091 A256092 A256093 * A256095 A256096 A256097

nonn,easy

Wolfdieter Lang, Mar 14 2015

approved