A250251 Fixed points of A250249 and A250250.

1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 23, 24, 25, 26, 28, 29, 30, 31, 32, 34, 35, 36, 37, 38, 40, 41, 43, 44, 46, 47, 48, 49, 50, 52, 53, 56, 58, 59, 60, 61, 62, 64, 67, 68, 70, 71, 72, 74, 76, 77, 79, 80, 82, 83, 86, 88, 89, 92, 94, 96, 97, 98, 100, 101, 104, 106, 107, 109, 112, 113, 116, 118, 120, 121

Offset: 1

Author

Antti Karttunen, Nov 18 2014

Keywords

• nonn

Comments

Numbers for which A250249(n) = n (equally: A250250(n) = n).

If n is a member, then 2n is also a member. If any 2n is a member, then n is also a member. If n is a member, then the n-th prime, p_n (= A000040(n)) is also a member. If p_n is a member, then its index n is also a member. Thus the sequence is completely determined by its odd nonprime terms: 1, 9, 15, 25, ..., (A249730) and is obtained as a union of their multiples with powers of 2, and all prime recurrences that start with those values: A007097 U A057450 U A057451 U A057452 U A057453 U ..., etc.

Links

• Antti Karttunen, Table of n, a(n) for n = 1..801

Crossrefs

Complement: A249729.

Subsequences: A249730, and also A007097, A057450, A057451, A057452, A057453, etc.

Cf. also A245823, A250249, A250250.