A352670 a(n) is the smallest positive integer not yet in the sequence such that the binary representation of a(n) AND a(n-1) contains exactly two 1-bits, starting a(1) = 3.

3, 7, 5, 13, 9, 11, 10, 14, 6, 15, 12, 28, 20, 21, 17, 19, 18, 22, 26, 23, 25, 24, 27, 35, 31, 37, 29, 39, 30, 38, 34, 42, 40, 41, 33, 43, 44, 36, 45, 49, 47, 50, 46, 51, 48, 52, 56, 53, 58, 74, 59, 67, 55, 69, 61, 71, 54, 57, 73, 63, 70, 62, 75, 65, 77, 60

Offset: 1

Author

Alois P. Heinz, Mar 28 2022

Keywords

• nonn
• look

Comments

This is a permutation of the positive nonpowers of 2, or of { A057716 } \ {0}.

Links

• Alois P. Heinz, Table of n, a(n) for n = 1..65536
• Wikipedia, Bitwise operation

Crossrefs

Cf. A000079, A057716, A109812, A226077.