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

1,1

Comments

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

Links

Table of n, a(n) for n=1..81.

Formula

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

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.

Sequence in context: A023803 A353511 A122132 * A347243 A325389 A020662

Adjacent sequences: A347245 A347246 A347247 * A347249 A347250 A347251

Keyword

nonn

Author

Antti Karttunen, Aug 28 2021

Status

approved