A071347 a(n) = greatest positive r <= n, such that the origin-centered 4d-sphere of radius sqrt(r) touches A071345(n) lattice points.

1, 3, 9, 15, 18, 30, 42, 54, 78, 90, 114, 126, 150, 186, 210, 210, 270, 270, 330, 390, 390, 450, 510, 570, 594, 630, 630, 750, 810, 882, 930, 990, 1050, 1050, 1170, 1170, 1350, 1386, 1470, 1530, 1650, 1710, 1710, 1890, 1890, 1890, 1890, 2250, 2310

Offset: 1

Author

Hugo Pfoertner, May 22 2002

Keywords

• easy
• nonn

Examples

			a(4)=15 because the largest 4d-sphere with radius <= 4 to touch A071345(4)=192 points has radius sqrt(15).
		

Crossrefs

Cf. A071339-A071346.

Programs

FORTRAN

See A071339.

Extensions

Edited by Don Reble, Nov 06 2005