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 A124580 #4 Mar 30 2012 17:31:21
%S A124580 1,9,15,31,36,40,47,165,237,330,354,357,365,402,406,421,426,794,797,
%T A124580 813,885,894,897,905,914,1257,1281,1290,1298,1301,1337,1522,1526,1545,
%U A124580 1842,1865,2094,2098,2118,2121,2137,2569,3598,4602,4609,4621,4629,4726,4729
%N A124580 Where A124579 has two successive identical values.
%C A124580 Except for a(2), a(5) & a(6) none of these duplicates involve zeros.
%H A124580 Robert G. Wilson v, <a href="/A124580/b124580.txt">Table of n, a(n) for n=1..9066</a>
%e A124580 Interval 10^n . # of -1 ...# of 0 . # of 1 # of terms
%e A124580 ............0.........0.........0.........1........1
%e A124580 ............1.........4.........3.........3........1
%e A124580 ............2........30........39........31........5
%e A124580 ............3.......303.......392.......305.......18
%e A124580 ............4......3053......3917......3030.......57
%e A124580 ............5.....30421.....39206.....30373......189
%e A124580 ............6....303857....392074....304069......636
%e A124580 ............7...3039127...3920709...3040164.....1176
%e A124580 ............8..30395383..39207306..30397311.....4621
%e A124580 ............9.303963673.392072876.303963451....15952
%t A124580 p = q = y = z = a = 0; s = {}; Do[ q = Switch[ MoebiusMu@n, -1, y++, 0, z++, 1, a++ ]; If[p == q, AppendTo[s, n - 1]]; p = q, {n, 5000}]; s
%Y A124580 Cf. A124579, Column 2 = A063035, Column 1 + Column 3 = A053462.
%K A124580 nonn
%O A124580 1,2
%A A124580 _Robert G. Wilson v_, Nov 05 2006, Nov 12 2006