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 A330955 #8 Jan 05 2020 12:57:33 %S A330955 0,0,0,1,0,1,0,1,0,1,2,2,2,2,2,3,0,1,2,2,2,2,2,3,0,1,2,3,2,2,2,3,0,1, %T A330955 2,2,4,4,4,4,4,4,4,5,4,5,4,5,4,4,4,5,4,5,6,6,4,4,6,6,6,6,6,7,0,1,2,2, %U A330955 4,4,4,4,4,4,4,5,4,5,4,5,4,4,4,5,4,5,6 %N A330955 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 greatest possible value of x AND y (where AND denotes the bitwise AND operator). %H A330955 Rémy Sigrist, <a href="/A330955/a330955.txt">C program for A330955</a> %H A330955 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a> %e A330955 For n = 5: %e A330955 - the binary representation of 5 is "101", %e A330955 - the possible values for (x, y), restricted to x >= y without loss of generality, are: %e A330955 bin(5) x y x AND y %e A330955 ------- - - ------- %e A330955 "101" 5 0 0 %e A330955 "1/01" 1 1 1 %e A330955 "10/1" 2 1 0 %e A330955 "1/0/1" 3 0 0 %e A330955 - hence a(5) = 1. %o A330955 (C) See Links section. %Y A330955 See A330925 for similar sequences. %Y A330955 Cf. A327188. %K A330955 nonn,base %O A330955 0,11 %A A330955 _Rémy Sigrist_, Jan 04 2020