A330220 Numbers whose representation in base 2^w contains only the digit 2^k for some w and k such that 0 <= k < w

0, 1, 2, 3, 4, 5, 7, 8, 9, 10, 15, 16, 17, 18, 21, 31, 32, 33, 34, 36, 42, 63, 64, 65, 66, 68, 73, 85, 127, 128, 129, 130, 132, 136, 146, 170, 255, 256, 257, 258, 260, 264, 273, 292, 341, 511, 512, 513, 514, 516, 520, 528, 546, 585, 682, 1023, 1024, 1025, 1026

Offset

1,3

Comments

This is a subsequence of A295235.

For any k > 0, there are k nonzero terms with k binary digits.

Odd terms are A064896.

Links

Table of n, a(n) for n=1..59.

Example

The representation of 546 in base 2^4 is "222", so 546 belongs to the sequence.

Prog

(PARI) is(n) = { for (w=1, max(1, #binary(n)), my (d=if (n, digits(n, 2^w), [0])); if (#Set(d)==1 && hammingweight(d[1])<=1, return (1))); return (0) }

Crossrefs

Cf. A064896, A295235.

Sequence in context: A299767 A129268 A271317 * A039169 A156068 A039263

Adjacent sequences: A330217 A330218 A330219 * A330221 A330222 A330223

Keyword

nonn,base

Author

Rémy Sigrist, Dec 06 2019

Status

approved