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 A138719 #2 Mar 30 2012 17:33:54 %S A138719 101,101,110011,111000111,111110000011111,111111110000000011111111, %T A138719 111111111111100000000000001111111111111, %U A138719 111111111111111111111000000000000000000000111111111111111111111 %N A138719 Concatenation of k digits 1, k digits 0 and k digits 1, where k is the n-th positive Fibonacci number. %Y A138719 Cf. A000045, A134803, A138709, A138722. %K A138719 base,easy,nonn %O A138719 1,1 %A A138719 _Omar E. Pol_, Mar 29 2008