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 A180108 #5 Jul 14 2015 00:16:22
%S A180108 0,1,2,1,2,4,2,3,6,3,4,8,9,10,5,6,12,6,7,14,15,16,8,9,18,9,10,20,21,
%T A180108 22,11,12,24,25,26,27,28,14,15,30,15,16,32,33,34,35,36,18,19,38,39,40,
%U A180108 20,21,42,21,22,44,45,46,23,24,48,49,50,51,52,26,27,54,55,56,57,58,29,30
%N A180108 Integers where the primes are split into two consecutive numbers.
%C A180108 The even prime 2 is not split.
%e A180108 The prime 29 is split into 14 and 15.
%t A180108 f[n_] := If[ !PrimeQ@ n || n == 2, n, {(n - 1)/2, (n + 1)/2}]; Array[ f, 60, 0] // Flatten (* _Robert G. Wilson v_, Aug 15 2010 *)
%Y A180108 Cf. A000040, A002808.
%K A180108 base,nonn
%O A180108 0,3
%A A180108 _Parthasarathy Nambi_, Aug 10 2010
%E A180108 More terms from _Robert G. Wilson v_, Aug 15 2010