A244990 After 1, numbers whose greatest prime factor is a prime with an even index; n such that A061395(n) is even.

1, 3, 6, 7, 9, 12, 13, 14, 18, 19, 21, 24, 26, 27, 28, 29, 35, 36, 37, 38, 39, 42, 43, 48, 49, 52, 53, 54, 56, 57, 58, 61, 63, 65, 70, 71, 72, 74, 76, 78, 79, 81, 84, 86, 87, 89, 91, 95, 96, 98, 101, 104, 105, 106, 107, 108, 111, 112, 113, 114, 116, 117, 122, 126, 129, 130, 131, 133, 139, 140, 142, 143, 144

Offset: 1

Author

Antti Karttunen, Jul 21 2014

Keywords

• nonn

Comments

Equally, after 1, natural numbers n such that A006530(n) is in A031215.

A122111 maps each one of these numbers to a unique term of A028260 and vice versa.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..10001

Crossrefs

Complement: A244991.

Cf. A006530, A028260, A031215, A061395, A122111, A244988, A244321, A244322.

Formula

For all n, A244988(a(n)) = n.