A387161 Numbers k for which A324644(k)/A324198(k) = 3.

2, 14, 26, 62, 74, 86, 122, 134, 146, 152, 176, 182, 206, 212, 224, 254, 272, 290, 302, 314, 326, 338, 368, 386, 422, 428, 434, 446, 476, 542, 554, 566, 578, 590, 626, 632, 644, 656, 662, 674, 680, 722, 734, 752, 782, 794, 812, 842, 848, 854, 866, 890, 914, 920, 926, 974, 1046, 1058, 1082, 1088, 1094, 1136, 1154

Offset: 1

Author

Antti Karttunen, Aug 28 2025

Keywords

• nonn
• new

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10000
• Index entries for sequences related to primorial base
• Index entries for sequences related to sigma(n)

Crossrefs

Subsequences: A387163 (terms whose abundancy >= 3).

Cf. A000203, A276086, A324198, A324644, A351458.

Cf. also A364286.

Programs

PARI

A276086(n) = { my(m=1, p=2); while(n, m *= (p^(n%p)); n = n\p; p = nextprime(1+p)); (m); };
is_A387161(n) = { my(u=A276086(n)); (gcd(sigma(n), u)==3*gcd(n, u)); };