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

1,2

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

Formula

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

Prog

(Scheme, with Antti Karttunen's IntSeq-library)
(define A244990 (MATCHING-POS 1 1 (COMPOSE even? A061395)))

Crossrefs

Complement: A244991.

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

Sequence in context: A333552 A324929 A135412 * A191990 A289059 A286686

Adjacent sequences: A244987 A244988 A244989 * A244991 A244992 A244993

Keyword

nonn

Author

Antti Karttunen, Jul 21 2014

Status

approved