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 A087378 #7 Dec 05 2013 19:56:21 %S A087378 2,4,9,26,93,144,205,120,1839,532,897,1140,1681,2490,2985,4312,5607, %T A087378 1344,9569,30612,19353,16162,15705,81486,28253,31932,19635,35644, %U A087378 82101,44322,43361,34092,89721,162176,134547,173394,31433,404634,212739 %N A087378 Smallest k such that both k-n and k+n are primes and there are no primes between them. %C A087378 For n>0, a(n) = arithmetic mean of the smallest pair of two consecutive primes with a difference 2n. %F A087378 a(n) = A000230(n)+n. - _David Wasserman_, May 24 2005 %e A087378 a(5) = 144 as 139 and 149 both are prime and all numbers from 140 to 148 are composite. %K A087378 nonn %O A087378 0,1 %A A087378 _Amarnath Murthy_, Sep 09 2003 %E A087378 More terms from _David Wasserman_, May 24 2005 %E A087378 Edited by _Franklin T. Adams-Watters_, Oct 26 2006