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 A106748 #7 Jul 30 2015 22:49:32
%S A106748 1,113,1131132,1131132113113213,113113211311321311311321131132131132,
%T A106748 113113211311321311311321131132131132113113211311321311311321131132131132113113213
%N A106748 Define the morphism f: 1->113, 2->13, 3->2 and let a(0) = 1; then a(n+1) = f(a(n)).
%D A106748 E. Bombieri and J. Taylor, Which distribution of matter diffracts? An initial investigation, in International Workshop on Aperiodic Crystals (Les Houches, 1986), J. de Physique, Colloq. C3, 47 (1986), C3-19 to C3-28.
%t A106748 FromDigits /@ NestList[ Flatten[ # /. {1 -> {1, 1, 3}, 2 -> {1, 3}, 3 -> 2}] &, {1}, 5] (* _Robert G. Wilson v_, May 17 2005 *)
%Y A106748 Cf. A106749.
%K A106748 nonn
%O A106748 0,2
%A A106748 _N. J. A. Sloane_, May 16 2005
%E A106748 More terms from _Robert G. Wilson v_, May 17 2005