login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A225093 a(1)=2, a(2)=3, for n>=3, a(n) is the n-th number which is obtained by application of Eratosthenes-like sieve to A225091. 11

%I

%S 2,3,7,13,5,11,31,43,37,29,73,79,19,41,97,59,103,127,71,157,17,163,89,

%T 23,107,211,181,241,199,131,67,101,61,271,277,149,313,307,47,367,173,

%U 397,331,409,179,197,191,457,251,499,239,233,487,139,547,523,571,151

%N a(1)=2, a(2)=3, for n>=3, a(n) is the n-th number which is obtained by application of Eratosthenes-like sieve to A225091.

%C We conjecture that every term is prime; moreover, we conjecture that the sequence is a permutation of the sequence of all primes. - _Vladimir Shevelev_, Dec 17 2014

%H Peter J. C. Moses, <a href="/A225093/b225093.txt">Table of n, a(n) for n = 1..2000</a>

%t Flatten[{{2,3}, DeleteDuplicates[Select[Map[#/(2^IntegerExponent[#,2])&[Total[IntegerDigits[7^#]]]&, Range[200]], PrimeQ]]}] (* _Peter J. C. Moses_, Apr 27 2013 *)

%Y Cf. A000040, A221858, A225017, A225039, A225040, A225091, A251964, A252280, A252281, A252282, A252283.

%K nonn

%O 1,1

%A _Vladimir Shevelev_, Apr 27 2013

%E More terms from _Peter J. C. Moses_, Apr 27 2013

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 24 02:42 EDT 2019. Contains 325287 sequences. (Running on oeis4.)