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.
%I A187812 #16 Feb 13 2013 23:58:29 %S A187812 89,23,13,23,17,5,5,5,5,11,11,71,2,2,2,2,29,2,101,59,2,107,107,239, %T A187812 197,71,419,107,197,347,311,179,281,827,1277,269,827,569,1481,1667, %U A187812 1031,1019,617,2081,4337,5651,3767,641,3119,2789,2999,11699,4241,8219,4127 %N A187812 a(n) is the smallest prime(m) such that the interval (prime(m)*n, prime(m+1)*n) contains exactly four primes. %C A187812 Conjecture. In the supposition that there are infinitely many twin primes, every term beginning with the sixth is 2 or in A001359 (lesser of twin primes). %H A187812 Alois P. Heinz, <a href="/A187812/b187812.txt">Table of n, a(n) for n = 2..100</a> %F A187812 lim a(n) = infinity, as n goes to infinity. %e A187812 Let n=6, and consider intervals of the form (6*prime(m), 6*prime(m+1)). %e A187812 For 2, 3, 5, ..., the intervals (12,18), (18,30), (30,42), (42,66), (66,78), (78,102), (102,114)... contain 2, 3, 3, 5, 3, 5, 4,... primes. Hence the smallest such prime is 17. %Y A187812 Cf. A195871, A187809, A187810. %K A187812 nonn %O A187812 2,1 %A A187812 _Vladimir Shevelev_ and _Peter J. C. Moses_, Jan 07 2013