A145255 a(n) = the smallest positive integer that is non-coprime to n and has the same number of 0's in its binary representation as n has.

2, 3, 4, 5, 2, 7, 8, 9, 4, 11, 4, 13, 2, 3, 16, 17, 8, 19, 8, 9, 4, 23, 8, 10, 4, 6, 4, 29, 2, 31, 32, 33, 16, 20, 16, 37, 8, 9, 16, 41, 8, 43, 8, 9, 4, 47, 16, 35, 8, 9, 8, 53, 4, 5, 8, 9, 4, 59, 4, 61, 2, 3, 64, 65, 32, 67, 32, 33, 16, 71, 32, 73, 16, 18, 16, 35, 8, 79, 32, 33, 16, 83, 16

Offset: 2

Author

Leroy Quet, Oct 05 2008

Keywords

• nonn
• look
• base

Links

• Michael De Vlieger, Table of n, a(n) for n = 2..16384

Crossrefs

Cf. A145254, A145256, A145257.

Programs

Mathematica

Table[Function[k, SelectFirst[Range[2, n], And[! CoprimeQ[#, n], DigitCount[#, 2, 0] == k] &]]@ DigitCount[n, 2, 0], {n, 2, 84}] (* Michael De Vlieger, Oct 26 2017 *)

Extensions

Extended by Ray Chandler, Nov 03 2008