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 A187869 #7 Mar 30 2012 16:52:01 %S A187869 1,12,123,1234,14325,143256,1432567,12347658,123476589,12347658910, %T A187869 1234710985611,123471098561112,12347651211891013,1234761310981112514, %U A187869 123476131098111251415,12347651211815149101316,1234765121189101316151417,123476589101316151417121118 %N A187869 a(n) is the concatenation of the numbers appearing in row n of the lexicographically earliest prime pyramid (A051237). %Y A187869 Cf. A051237. %K A187869 base,nonn %O A187869 1,2 %A A187869 _N. J. A. Sloane_, Mar 14 2011