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 A087309 #11 Dec 05 2013 19:56:20 %S A087309 1,3,7,23,29,157,505,1139,1211,2089,5161,5293,6347,10717,14233,28213, %T A087309 31451,72965,119029,121603,124177,611261,632171,2003171,2012771 %N A087309 Least number that ends an arithmetic progression of n numbers with the same prime signature. %C A087309 Final terms of the arithmetic progressions described in A086786. %C A087309 Main diagonal of A086786. %H A087309 <a href="/index/Pri#primes_AP">Index entries for sequences related to primes in arithmetic progressions</a> %F A087309 a(n)=A087308(n)+(n-1)*A087310(n). - _R. J. Mathar_, Oct 19 2007 %Y A087309 Cf. A086786, A087308, A087310, A114659, A114662, A114669. %K A087309 more,nonn %O A087309 1,2 %A A087309 _Amarnath Murthy_, Sep 02 2003 %E A087309 Edited and extended by _David Wasserman_, Jan 08 2006 %E A087309 Further edited by _N. J. A. Sloane_, Jun 30 2008 at the suggestion of R. J. Mathar.