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 A101231 #9 Jan 03 2013 12:39:31 %S A101231 2,29,67,179,941,4079,20389,65267,224563,978863,6448979,47247763, %T A101231 309550999,2150787839,13925010299 %N A101231 a(n) = n-th prime of Erdős-Selfridge classification n-. %C A101231 Diagonalization of the Erdős-Selfridge classification of primes. %D A101231 R. K. Guy, Unsolved Problems in Number Theory, A18. %e A101231 a(1) = 2 because 2 is the first element of A005109. %e A101231 a(2) = 29 because 29 is the 2nd element of A005110. %e A101231 a(3) = 67 because 67 is the 3rd element of A005111. %e A101231 a(4) = 179 because 179 is the 4th element of A005112. %Y A101231 Cf. A056637, A005109, A005110, A005111, A005112, A005113, A081424, A081425, A081426, A081427, A081429. %K A101231 nonn,more %O A101231 1,1 %A A101231 _Jonathan Vos Post_, Dec 15 2004 %E A101231 More terms from _R. J. Mathar_, May 02 2007