A071340 a(n) = least positive r <= n such that the origin-centered circle of radius sqrt(r) touches A071339(n) lattice points.

0, 1, 1, 5, 5, 25, 25, 25, 25, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 325, 325, 325, 325, 325, 325, 325, 325, 325, 325, 325, 325, 325, 325, 325, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105, 1105

Offset: 0

Author

Hugo Pfoertner, May 22 2002

Keywords

• easy
• nonn

Examples

			a(4)=5 because the smallest circle to touch A071339(4)=8 points has radius sqrt(5).
		

Links

• Hugo Pfoertner, Illustration

Crossrefs

Cf. A071339-A071347.

Programs

FORTRAN

See A071339.

Extensions

Edited by Don Reble, Nov 06 2005