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%I #10 Feb 05 2020 08:58:54
%S 1,2,2,4,2,2,4,8,2,2,2,12,4,5,8,16,2,2,2,4,2,2,12,24,4,4,5,6,8,10,16,
%T 32,2,2,2,4,2,2,4,40,2,2,2,9,12,16,24,48,4,4,4,4,5,5,6,56,8,9,10,12,
%U 16,21,32,64,2,2,2,4,2,2,4,8,2,2,2,16,4,26,40
%N a(n) is the least positive k such that n AND floor(n/k) = 0 (where AND denotes the bitwise AND operator).
%C This sequence has similarities with A261891; here we divide and round down, there we multiply, in order to obtain a number with no common bit with the original.
%H Rémy Sigrist, <a href="/A331985/b331985.txt">Table of n, a(n) for n = 0..8192</a>
%F a(n) = 2 iff n is a positive Fibbinary number (A003714).
%e For n = 3:
%e - 3 AND floor(3/1) = 3,
%e - 3 AND floor(3/2) = 1,
%e - 3 AND floor(3/3) = 1,
%e - 3 AND floor(3/4) = 0,
%e - hence a(3) = 4.
%o (PARI) a(n) = for (k=1, oo, if (bitand(n,n\k)==0, return (k)))
%Y Cf. A003714, A261891, A332011.
%K nonn,base
%O 0,2
%A _Rémy Sigrist_, Feb 03 2020
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