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 A102167 #8 Mar 31 2012 13:46:51 %S A102167 7,19,20,23,24,25,26,27,28,29,30,34,35,36,37,38,39,40,45,46,47,48,49, %T A102167 50,56,57,58,59,60,67,68,69,70,78,79,80,88,90,99,100,118,122,133,144, %U A102167 155,166,177 %N A102167 Lightest finite strictly increasing sequence of integers showing once and only once every pair of digits from [00] to [99]. The "weight" of such a sequence is the sum of all its a(n). Weight of this sequence is 2995. %C A102167 It seems that it is only a conjecture that this sequence is really the lightest! - _N. J. A. Sloane_, Mar 15 2005 %e A102167 Sequence starts with 7 19 20 23... showing pairs [71], [19], [92], [20], [02], [23]... %K A102167 base,easy,nonn,fini,full %O A102167 1,1 %A A102167 Geoff Bailey, Richard Tucker, "Alex" and _Eric Angelini_, Feb 16 2005; revised Mar 15 2005