cp's OEIS Frontend

A179240 a(n) is the smallest prime q > a(n-1) such that, for the previous prime p and the following prime r, the fraction (q-p)/(r-q) has denominator equal to A006843(n) (or 0, if such a prime does not exist).

%I A179240 #20 Mar 30 2012 18:52:54
%S A179240 5,11,17,19,29,41,47,67,73,97,101,359,367,379,383,389,397,419,421,449,
%T A179240 467,547,613,631,647,683,691,733,769,797,811,929,941,1021,1087,1153,
%U A179240 1181,1193,1249,1709,1721,1747,1847,1889,2017,2153,2357
%N A179240 a(n) is the smallest prime q > a(n-1) such that, for the previous prime p and the following prime r, the fraction (q-p)/(r-q) has denominator equal to A006843(n) (or 0, if such a prime does not exist).
%C A179240 Conjecture: a(n) > 0 for all n.
%e A179240 For n = 1..3, A006843(n) = 1, and p,q,r have to obey the condition
%e A179240 r-q | q-p. Thus a(1) = 5, a(2) = 11, a(3) = 17.
%Y A179240 Cf. A006843, A168253, A179210, A179234, A179256, A001223
%K A179240 nonn
%O A179240 1,1
%A A179240 _Vladimir Shevelev_, Jan 06 2011
%E A179240 More terms from _Alois P. Heinz_, Jan 06 2011