A347248 Numbers k such that the greatest prime factor of A000593(k) [the sum of odd divisors of k] is less than the greatest prime factor of k itself.

2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 22, 23, 24, 26, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 51, 52, 53, 55, 56, 57, 58, 59, 60, 61, 62, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 76, 77, 78, 79, 80, 82, 83, 84, 85, 86, 87, 88, 89, 91, 92, 93, 94, 95, 96

Offset: 1

Author

Antti Karttunen, Aug 28 2021

Keywords

• nonn

Comments

a(126) = 153 is the first term that is not present in A122132.

Crossrefs

Cf. A000593, A006530.

Positions of zeros in A347246 (which is the characteristic function of the complementof this sequence, A347247).

Apart from its initial 1, A347243 is a subsequence of this sequence.

Cf also A122132.

Formula

{k such that A006530(A000593(k)) < A006530(k)}.