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 A147756 #8 May 24 2014 13:28:21 %S A147756 4,3,10,7,36,21,54,15,136,73,42,91,204,109,238,31,528,273,146,307,660, %T A147756 85,182,375,792,409,858,219,924,477,990,63,2080,1057,546,1123,292, %U A147756 1189,614,1255,2600,1321,170,1387,2860,365,750,1519,3120,1585,3250,819,3380 %N A147756 a(n) = the smallest integer m such that n = (the largest integer that, when represented in binary, occurs at least twice as a substring in the binary representation of m). %C A147756 The substrings (each equal to the binary representation of n) may overlap in the binary representation of a(n). a(n) = the smallest positive integer such that A147755(a(n)) = n. %H A147756 Alois P. Heinz, <a href="/A147756/b147756.txt">Table of n, a(n) for n = 0..8191</a> %e A147756 21 in binary is 10101. 101 (5 in decimal) occurs twice in 10101: (101)01 and 10(101). Since no larger integer (when represented in binary) occurs more than once within 10101 and since no smaller integer (represented in binary) contains the substring 101 within it at least twice, then a(5) = 21. %Y A147756 Cf. A147755. %K A147756 base,nonn %O A147756 0,1 %A A147756 _Leroy Quet_, Nov 11 2008 %E A147756 Extended by _Ray Chandler_, Nov 14 2008