A340718 a(n) is the least k such that A340717(k) = n.

0, 1, 3, 5, 7, 9, 11, 15, 17, 19, 21, 23, 27, 31, 33, 35, 37, 39, 43, 45, 47, 51, 55, 63, 65, 67, 69, 71, 73, 75, 77, 79, 83, 85, 87, 91, 93, 95, 99, 103, 107, 111, 119, 127, 129, 131, 133, 135, 137, 139, 141, 143, 147, 149, 151, 153, 155, 157, 159, 163, 165

Offset

0,3

Comments

These are also the numbers k such that k <= A030101(k).

All terms, except a(0) = 0, are odd.

For any k > 0, there are A005418(k) terms with k+1 binary digits.

A000225 and A006995 are subsequences.

Links

Rémy Sigrist, Table of n, a(n) for n = 0..8383

Example

k          | 0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15, ...
A340717(k) | 0,  1,  1,  2,  1,  3,  2,  4,  1,  5,  3,  6,  2,  6,  4,  7, ...
n          | 0,  1,      2,      3,      4,      5,      6,              7, ...
a(n)       | 0,  1,      3,      5,      7,      9,     11,             15, ...

Prog

(PARI) is(n) = n <= fromdigits(Vecrev(binary(n)), 2)

Crossrefs

Cf. A000225, A005418, A006995, A030101, A340717.

Sequence in context: A043325 A023692 A355743 * A155113 A327260 A256862

Adjacent sequences: A340715 A340716 A340717 * A340719 A340720 A340721

Keyword

nonn,base

Author

Rémy Sigrist, Jan 17 2021

Status

approved