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 A330959 #7 Jan 05 2020 12:58:20 %S A330959 0,1,1,0,1,0,3,2,1,0,0,1,0,1,1,0,1,0,0,1,0,1,1,0,3,2,1,0,4,5,5,4,1,0, %T A330959 0,1,0,1,1,0,0,1,1,0,1,0,3,2,0,1,1,0,1,0,0,1,2,3,0,1,0,1,1,0,1,0,0,1, %U A330959 0,1,1,0,0,1,1,0,1,0,3,2,0,1,1,0,1,0,0 %N A330959 For any n >= 0: consider all pairs of numbers (x, y) whose binary representations can be interleaved (or shuffled) to produce the binary representation of n (possibly with leading zeros); a(n) is the least possible value of x XOR y (where XOR denotes the bitwise XOR operator). %H A330959 Rémy Sigrist, <a href="/A330959/a330959.txt">C program for A330959</a> %H A330959 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %e A330959 For n = 5: %e A330959 - the binary representation of 5 is "101", %e A330959 - the possible values for (x, y), restricted to x >= y without loss of generality, are: %e A330959 bin(5) x y x XOR y %e A330959 ------- - - ------- %e A330959 "101" 5 0 5 %e A330959 "1/01" 1 1 0 %e A330959 "10/1" 2 1 3 %e A330959 "1/0/1" 3 0 3 %e A330959 - hence a(5) = 0. %o A330959 (C) See Links section. %Y A330959 See A330925 for similar sequences. %Y A330959 Cf. A327187. %K A330959 nonn,base %O A330959 0,7 %A A330959 _Rémy Sigrist_, Jan 04 2020