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 A098153 #3 Mar 30 2012 17:36:43 %S A098153 1,11,101,10101,100111,1001001,1000111,1101001,1101001,1101001, %T A098153 1101001,1101001,1101001,1101001,1101001,1101001,1101001,1101001, %U A098153 1101001,1101001,1101001,1101001,1101001,1101001,1101001,1101001,1101001 %N A098153 Summarize the previous term in binary (in increasing order). %C A098153 Similar to A005151 but uses base 2: Let a(1)=1. Describing a(1) as "one 1" again gives a(2)=11 (same digit string as A005151 and similar sequences), but describing a(2) as "two 1's" gives a(3)=101 when the frequency of digit occurrence is written in binary and followed by the digit counted. %F A098153 a(n) = 1101001 for all n >= 8 (see example). %e A098153 Summarizing a(8) = 1101001 in increasing digit order, there are "three 0's, four 1's", so concatenating 11 0 100 1 gives a(9) = 1101001 (=a(10)=a(11)=...). %Y A098153 Cf. A098154 (ternary), A098155 (base 4), A005151 (decimal and digit strings for all other bases b >= 5). %K A098153 base,easy,nonn %O A098153 1,2 %A A098153 _Rick L. Shepherd_, Aug 29 2004