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 A130602 #2 Mar 31 2012 20:55:21 %S A130602 11,1111,11,111111,11,1111,11111111,1111,11,111111,1111111111,111111, %T A130602 11,1111,11111111,111111111111,11111111,1111,11,111111,1111111111, %U A130602 11111111111111,1111111111,111111,11,1111,11111111,111111111111 %N A130602 A shell geometric model of the atomic nucleus. %C A130602 11 is equal to 2 protons. 1111 is equal 2+2 protons. 111111 is equal 2+2+2 protons... %C A130602 Repunit numbers represent the subshells. %e A130602 See the model in the entry: A130517, A130556. %Y A130602 Cf. A056951, A130517, A130556. %K A130602 nonn %O A130602 1,1 %A A130602 _Omar E. Pol_, Aug 10 2007, Aug 12 2007