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

0,1

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.

Links

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

Example

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

Crossrefs

Cf. A261416, A261461, A261922.

See A262289 for the "positive" version.

Sequence in context: A141030 A221168 A194084 * A297871 A292130 A291971

Adjacent sequences: A262278 A262279 A262280 * A262282 A262283 A262284

Keyword

nonn,base

Author

N. J. A. Sloane, Sep 17 2015

Extensions

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

Status

approved