cp's OEIS Frontend

A330958 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 OR y (where OR denotes the bitwise OR operator).

%I A330958 #7 Jan 05 2020 12:58:07
%S A330958 0,1,1,1,1,1,3,3,1,1,2,3,2,3,3,3,1,1,2,3,2,3,3,3,3,3,3,3,6,7,7,7,1,1,
%T A330958 2,3,2,3,3,3,3,3,3,3,5,5,7,7,3,3,3,3,5,5,6,7,6,7,6,7,6,7,7,7,1,1,2,3,
%U A330958 2,3,3,3,3,3,3,3,5,5,7,7,3,3,3,3,5,5,6
%N A330958 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 OR y (where OR denotes the bitwise OR operator).
%H A330958 Rémy Sigrist, <a href="/A330958/a330958.txt">C program for A330958</a>
%H A330958 <a href="/index/Bi#binary">Index entries for sequences related to binary expansion of n</a>
%e A330958 For n = 5:
%e A330958 - the binary representation of 5 is "101",
%e A330958 - the possible values for (x, y), restricted to x >= y without loss of generality, are:
%e A330958   bin(5)   x  y  x OR y
%e A330958   -------  -  -  ------
%e A330958   "101"    5  0       5
%e A330958   "1/01"   1  1       1
%e A330958   "10/1"   2  1       3
%e A330958   "1/0/1"  3  0       3
%e A330958 - hence a(5) = 1.
%o A330958 (C) See Links section.
%Y A330958 See A330925 for similar sequences.
%Y A330958 Cf. A327186.
%K A330958 nonn,base
%O A330958 0,7
%A A330958 _Rémy Sigrist_, Jan 04 2020