A262281 a(n) = smallest nonnegative number, not a power of 2, that is not a substring of n in its binary representation.

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, 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, 3, 3, 5, 5, 3, 3, 3, 6, 5, 7, 5, 5, 3, 3, 3, 6, 3, 3, 7

Offset: 0

Author

N. J. A. Sloane, Sep 17 2015

Keywords

• nonn
• base

Comments

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

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

Examples

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

Links

• Hiroaki Yamanouchi, Table of n, a(n) for n = 0..10000

Crossrefs

Cf. A261416, A261461, A261922.

See A262289 for the "positive" version.

Extensions

a(23)-a(86) from Hiroaki Yamanouchi, Sep 20 2015