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

1,2

Comments

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

Links

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

Formula

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

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

Example

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.

Prog

(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

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).

Sequence in context: A067947 A279542 A053640 * A296991 A097755 A301704

Adjacent sequences: A344467 A344468 A344469 * A344471 A344472 A344473

Keyword

nonn

Author

Jianing Song, May 20 2021

Status

approved