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A140386 Erroneous version of A000040. 0

%I

%S 5,23,29,43,107,109,137,163,197,199,227,229,317,347,359

%N Erroneous version of A000040.

%C Original definition: Primes of the form ((x+y)/3+2)/(x-y), where x=prime and y=composite. The current sequence is largely incorrect because many values are missing; for example x=17 with y=16 contributes 13, x=23 with y=22 contributes 17, x=53 with y=52 contributes 37 etc. - _R. J. Mathar_, Apr 25 2010

%C All primes up to 100,000 are members. 835 is not a member. - _Charles R Greathouse IV_, Nov 25 2014

%o (PARI) is(n)=forprime(x=5,,my(y=(3*n*x-x-6)/(3*n+1));if(denominator(y)==1 && !isprime(y), return(isprime(n)))) \\ may loop forever if not a member; _Charles R Greathouse IV_, Nov 25 2014

%K dead

%O 1,1

%A _Juri-Stepan Gerasimov_, Aug 28 2008

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Last modified October 23 22:58 EDT 2019. Contains 328379 sequences. (Running on oeis4.)