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 A261812 #17 Sep 24 2015 01:36:33
%S A261812 -2,0,-1,1,0,0,-1,1,0,0,0,-1,1,0,0,0,-1,1,0,0,-1,1,0,0,0,-1,1,0,0,0,
%T A261812 -1,1,0,0,-1,1,0,0,0,-1,1,0,0,-1,1,0,0,0,-1,1,0,0,0,-1,1,0,0,-1,1,0,0,
%U A261812 0,-1,1,0,0,0,-1,1,0,0,-1,1,0,0,0,-1,1,0,0,0,-1,1,0,0,-1,1,0,0,0,-1,1,0,0,0,-1,1,0,0,-1,1,0,0,0,-1,1,0,0,0,-1,1,0,0,-1,1,0,0,0,-1,1,0,0,0,-1,1,0,0,-1,1,0,0,0,-1,1,0,0
%N A261812 First differences of A098842.
%F A261812 a(n) = A098842(n+1) - A098842(n).
%t A261812 Most@ Differences[ Last /@ Tally[ Max[ IntegerLength@#, 1] & /@ Fibonacci[ Range[0, 900]]]] (* _Giovanni Resta_, Sep 02 2015 *)
%o A261812 (Python)
%o A261812 import sys
%o A261812 import math
%o A261812 F = [F0,F1] = [0,1]
%o A261812 c = 2
%o A261812 c0 = 0
%o A261812 ll0 = 1
%o A261812 while True:
%o A261812 T = F[0] + F[1]
%o A261812 F[0] = F[1]
%o A261812 F[1] = T
%o A261812 dfn = 1 + math.log10(T)
%o A261812 ll = math.floor(dfn)
%o A261812 if ll0 != ll:
%o A261812 if c0 != 0:
%o A261812 sys.stdout.write("%d," % (c-c0))
%o A261812 ll0 = ll
%o A261812 c0 = c
%o A261812 c = 1
%o A261812 continue
%o A261812 c += 1
%K A261812 sign,base
%O A261812 1,1
%A A261812 _Andrew R. Reiter_, Sep 01 2015