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a(n) = smallest nonnegative number, not a power of 2, that is not a substring of n in its binary representation.
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%I #15 Sep 21 2015 14:28:37

%S 3,0,3,0,3,3,5,0,3,3,3,6,5,7,5,0,3,3,3,5,3,3,7,6,5,5,7,7,5,9,5,0,3,3,

%T 3,5,3,3,5,5,3,3,3,6,7,7,9,6,5,5,5,5,7,7,7,9,5,5,9,9,5,9,5,0,3,3,3,5,

%U 3,3,5,5,3,3,3,6,5,7,5,5,3,3,3,6,3,3,7

%N a(n) = smallest nonnegative number, not a power of 2, that is not a substring of n in its binary representation.

%C Similar to A261922, but if the smallest missing number is a power of 2, ignore it and look at the next-smallest missing number.

%C This is like applying A261922 not to n itself but to n plus a very large power of 2. Suggested by considering A261416.

%H Hiroaki Yamanouchi, <a href="/A262281/b262281.txt">Table of n, a(n) for n = 0..10000</a>

%e For n = 13 = 1101_2, we can see 0, 11 (3), 101 (5), 110 (6), but not 111 (7), so a(13)=7.

%Y Cf. A261416, A261461, A261922.

%Y See A262289 for the "positive" version.

%K nonn,base

%O 0,1

%A _N. J. A. Sloane_, Sep 17 2015

%E a(23)-a(86) from _Hiroaki Yamanouchi_, Sep 20 2015