A344470 Record values in A002654.

1, 2, 3, 4, 6, 8, 9, 12, 16, 18, 20, 24, 32, 36, 40, 48, 64, 72, 80, 96, 128, 144, 160, 192, 216, 256, 288, 320, 384, 432, 512, 576, 640, 768, 864, 960, 1024, 1152, 1280, 1536, 1728, 1920, 2048, 2304, 2560, 2880, 3072, 3456, 3840, 4096, 4608, 5120, 5760, 6144

Offset: 1

Author

Jianing Song, May 20 2021

Keywords

• nonn

Comments

Also numbers k such that A018782(m) > A018782(k) for all m > k.

Examples

			9 is a term because the circle with radius sqrt(4225) centered at the origin hits exactly 4*9 = 36 integer points, and any circle with radius < sqrt(4225) centered at the origin hits fewer than 36 points.
		

Links

• Jianing Song, Table of n, a(n) for n = 1..424

Crossrefs

Cf. A071383, A071385, A002654, A018782, A000005, A054994.

Records of Sum_{d|n} kronecker(m, d): A344472 (m=-3), this sequence (m=-4), A279542 (m=-6).

Programs

PARI

my(v=list(10^15), rec=0); for(n=1, #v, if(numdiv(v[n])>rec, rec=numdiv(v[n]); print1(rec, ", "))) \\ see program for A054994

Formula

a(n) = A071385(n+1)/4.

a(n) = A000005(A071383(n+1)) = A002654(A071383(n+1)).