A093832 Values of r such that N(r)/r^2 > Pi, where N(r) is the number of integer lattice points (x,y) inside or on a circle of radius r.

1, 2, 3, 5, 10, 15, 20, 35, 51, 52, 85, 100, 230, 247, 370, 425, 489, 725, 730, 1073, 1310, 1865, 1997, 2480, 2831, 3072, 3424, 3750, 3861, 3921, 4025, 4339, 4771, 4885, 5559, 5949, 6203, 6411, 7045, 7084, 7410, 7605, 8931, 9308, 9435, 9646, 10829, 10930

Offset: 1

Author

Eric W. Weisstein, Apr 17 2004

Keywords

• nonn

Links

• David Wasserman, Table of n, a(n) for n = 1..160
• Eric Weisstein's World of Mathematics, Gauss's Circle Problem.

Crossrefs

Cf. A000328, A000328, A093837.

Programs

PARI

A000328(n) = local(x, y, c, nn); c = 0; x = 0; nn = n*n; y = n; while (x < y, c += x; y--; x = sqrtint(nn - y*y)); 4*(n - y) + 8*c + (2*y + 1)^2; for (n = 1, 100000, if (A000328(n) > Pi*n*n, print(n))); \\ David Wasserman, Dec 05 2006

Extensions

Corrected and extended by David Wasserman, Dec 05 2006

Name corrected by Luis Mendo, Sep 24 2023