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%I #49 Sep 16 2017 03:41:41
%S 1,7,11,13,19,23,29,31,37,41,43,47,49,53,59,61,67,71,73,79,83,89,97,
%T 101,103,107,109,113,121,127,131,137,139,149,151,157,163,167,169,173,
%U 179,181,191,193,197,199,211,223,227,229,233,239,241,251,263,269,271,277,281,283,293,307,311
%N Powers of odd non-Fermat primes.
%C n is in the sequence if n = p^m where p is in A138889 and m >= 0. - _Robert Israel_, Sep 15 2017
%C The difference between two divisors of n is never a power of 2. The first number with this property that is not in the sequence is 91. - _Robert Israel_, Sep 15 2017
%C Subsequence of A061345.
%H Robert Israel, <a href="/A274915/b274915.txt">Table of n, a(n) for n = 1..10000</a>
%F A277994(a(n)) = 0.
%e 49 is in this sequence because 49 = 7^2 and 7 is not a Fermat prime.
%p N:= 500: # to get all terms <= N
%p P:= select(isprime, {seq(i,i=7..N,2)}) minus {seq(2^i+1, i=1..ilog2(N))}:
%p sort(convert(map(p -> seq(p^k,k=0..floor(log[p](N))), P), list)); # _Robert Israel_, Sep 15 2017
%Y Cf. A019434, A061345, A092506, A138889, A277994.
%K nonn,easy
%O 1,2
%A _Juri-Stepan Gerasimov_, Nov 11 2016
%E Edited, new name, and corrected by _Robert Israel_, Sep 15 2017
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