A364548 Numbers k such that k divides A005941(k).

1, 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24, 32, 40, 48, 64, 80, 96, 97, 128, 160, 192, 194, 256, 320, 345, 384, 388, 512, 549, 640, 690, 768, 776, 1024, 1093, 1098, 1280, 1380, 1536, 1552, 2048, 2186, 2196, 2560, 2760, 3072, 3104, 4096, 4372, 4392, 5120, 5520, 6144, 6208, 8192, 8744, 8784, 10240, 11040, 12288, 12416, 16384

Offset: 1

Author

Antti Karttunen, Jul 28 2023

Keywords

• nonn

Comments

Numbers k such that k divides 1+A156552(k).

Sequence A005940(A364546(.)) sorted into ascending order.

If k is a term, then also 2*k is present in this sequence, and vice versa.

Crossrefs

Cf. A005940, A005941, A156552, A364546.

Subsequences: A029747, A364549 (odd terms).

Cf. also A364497.

Programs

PARI

A005941(n) = { my(f=factor(n), p, p2=1, res=0); for(i=1, #f~, p = 1 << (primepi(f[i, 1])-1); res += (p * p2 * (2^(f[i, 2])-1)); p2 <<= f[i, 2]); (1+res) }; \\ (After David A. Corneth's program for A156552)
isA364548(n) = !(A005941(n)%n);