cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A217724 Smallest prime producing a gap with the next prime, the size of the gap being a composite number with 2n+1 as a factor.

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%I A217724 #9 Mar 27 2013 03:53:23
%S A217724 139,1831,1129,2971,1327,19333,81463,19609,44293,89689,173359,212701,
%T A217724 265621,544279,1100977,396733,1098847,370261,1349533,6752623,5518687,
%U A217724 6371401,10343761,2010733,4652353,33803689,83751121,38394127,39389989,79167733,142414669
%N A217724 Smallest prime producing a gap with the next prime, the size of the gap being a composite number with 2n+1 as a factor.
%C A217724 The "gap" is defined as the number of integers between two primes.  If the two primes are p1 and p2, then the size of the gap is p2-p1-1.
%C A217724 For at least n<=100, the gap is minimal and is 3*(2n+1).
%H A217724 Robert Price, <a href="/A217724/b217724.txt">Table of n, a(n) for n = 1..100</a>
%e A217724 For n=2, the required gap is a composite number with 5 (2n+1) as a factor.  The size of all gaps are odd, so gaps of 15, 25, 35, etc. are required.  The prime 1831 and its next prime of 1847 produces a gap of 15.  1831 is the smallest prime with this property.
%Y A217724 Cf. A067836.
%K A217724 nonn
%O A217724 1,1
%A A217724 _Robert Price_, Mar 21 2013