A338519 Integers that can be expressed as a product d*tau(d), where tau is the number of divisors function, in a single way.

1, 4, 6, 10, 12, 14, 22, 24, 26, 27, 32, 34, 38, 40, 46, 56, 58, 60, 62, 72, 74, 75, 80, 82, 84, 86, 88, 94, 104, 106, 118, 120, 122, 132, 134, 136, 140, 142, 146, 147, 152, 156, 158, 166, 168, 178, 184, 194, 202, 204, 206, 214, 218, 220, 226, 228, 232, 240, 248, 254

Offset: 1

Author

Michel Marcus, Nov 01 2020

Keywords

• nonn

Comments

Integers m such that A327166(m) = 1.

Links

• Seiichi Manyama, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000005, A038040, A327166, A338382.

Subsequences: A100484 (2*p), A079705 (3*p^2) that gives odd terms.

Cf. A338520 (similar for sum of divisors).

Programs

PARI

f(n) = sumdiv(n, d, d*numdiv(d) == n); \\ A327166
isok(n) = f(n)==1;