A336353 Numbers k such that sigma(k) does not have any prime factor larger than the largest prime factor of k.

1, 3, 5, 6, 7, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 26, 28, 29, 30, 31, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 51, 52, 53, 55, 56, 57, 58, 59, 61, 62, 65, 66, 67, 68, 69, 70, 71, 73, 74, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95

Offset: 1

Author

Antti Karttunen, Jul 19 2020

Keywords

• nonn

Comments

Note that the terms after 1 do not form a subsequence of A102750: the first counterexample is 343 = 7^3. See A336354.

Links

• Index entries for sequences where odd perfect numbers must occur, if they exist at all

Crossrefs

Positions of zeros in A336352.

Cf. A102750, A336317.

Subsequences: A000396, A001599, A065091, A105402, A333646 (see comment there), A336354.

Programs

PARI

isA336353(n) = !A336352(n);