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A225039 a(1)=2, a(2)=3, for n>=3, a(n) is the n-th number which is obtained by application Eratosthenes-like sieve to sequence: odd part of digit sum of 5^m, m>=1.

%I A225039 #28 Dec 24 2014 22:48:16
%S A225039 2,3,5,7,13,11,19,23,17,29,59,61,31,67,37,41,79,89,83,53,103,109,137,
%T A225039 149,151,127,167,43,211,191,199,97,181,197,193,241,269,113,233,257,
%U A225039 139,311,317,293,283,263,349,409,173,47,353,419,431,389,401,439,463,461
%N A225039 a(1)=2, a(2)=3, for n>=3, a(n) is the n-th number which is obtained by application Eratosthenes-like sieve to sequence: odd part of digit sum of 5^m, m>=1.
%C A225039 We conjecture that every term is prime; moreover, we conjecture that the sequence is a permutation of the sequence of all primes.
%C A225039 For comparison, if in the definition we replace 5^m with 13^m, then we obtain a sequence containing 25. - _Vladimir Shevelev_, Dec 17 2014
%H A225039 Peter J. C. Moses, <a href="/A225039/b225039.txt">Table of n, a(n) for n = 1..10000</a>
%t A225039 Flatten[{{2,3,5}, DeleteDuplicates[Select[Map[#/(2^IntegerExponent[#,2] 5^IntegerExponent[#,5])&[Total[IntegerDigits[5^#]]]&, Range[2,199]], PrimeQ]]}] (* _Peter J. C. Moses_, Apr 25 2013 *)
%Y A225039 Cf. A000040, A221858, A225017, A225040, A225093, A251964, A252280, A252281, A252282, A252283.
%K A225039 nonn,base
%O A225039 1,1
%A A225039 _Vladimir Shevelev_, Apr 25 2013
%E A225039 More terms from _Peter J. C. Moses_, Apr 25 2013