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%I #9 Nov 19 2014 00:05:08
%S 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,
%T 29,30,31,32,34,35,36,37,38,40,41,43,44,46,47,48,49,50,52,53,56,58,59,
%U 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
%N Fixed points of A250249 and A250250.
%C Numbers for which A250249(n) = n (equally: A250250(n) = n).
%C 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.
%H Antti Karttunen, <a href="/A250251/b250251.txt">Table of n, a(n) for n = 1..801</a>
%o (Scheme, with _Antti Karttunen_'s IntSeq-library)
%o (define A250251 (FIXED-POINTS 1 1 A250249))
%Y Complement: A249729.
%Y Subsequences: A249730, and also A007097, A057450, A057451, A057452, A057453, etc.
%Y Cf. also A245823, A250249, A250250.
%K nonn
%O 1,2
%A _Antti Karttunen_, Nov 18 2014
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