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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. 13

%I

%S 2,3,5,7,13,11,19,23,17,29,59,61,31,67,37,41,79,89,83,53,103,109,137,

%T 149,151,127,167,43,211,191,199,97,181,197,193,241,269,113,233,257,

%U 139,311,317,293,283,263,349,409,173,47,353,419,431,389,401,439,463,461

%N 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 We conjecture that every term is prime; moreover, we conjecture that the sequence is a permutation of the sequence of all primes.

%C 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 Peter J. C. Moses, <a href="/A225039/b225039.txt">Table of n, a(n) for n = 1..10000</a>

%t 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 Cf. A000040, A221858, A225017, A225040, A225093, A251964, A252280, A252281, A252282, A252283.

%K nonn,base

%O 1,1

%A _Vladimir Shevelev_, Apr 25 2013

%E More terms from _Peter J. C. Moses_, Apr 25 2013

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Last modified July 21 17:20 EDT 2019. Contains 325198 sequences. (Running on oeis4.)