A274089 Numbers repeated except that powers of 2 only appear once.

1, 2, 3, 3, 4, 5, 5, 6, 6, 7, 7, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14, 15, 15, 16, 17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 30, 30, 31, 31, 32, 33, 33, 34, 34, 35, 35, 36, 36, 37, 37, 38, 38, 39, 39, 40, 40

Offset

1,2

Links

Table of n, a(n) for n=1..74.

Formula

a(n) = floor(A057716(n) / 2). - Kevin Ryde, Apr 28 2024

Prog

(PARI) a(n) = n++; my(k=logint(n, 2)); n+=k; (n + bittest(n, k+1)) >> 1; \\ Kevin Ryde, Apr 28 2024
(Python)
def A274089(n): return n+(k:=n.bit_length())+bool(n+k&(1<<k))>>1 # Chai Wah Wu, Sep 05 2024

Crossrefs

Cf. A057716.

Conjectured to be (essentially) the first differences of A002960.

Sequence in context: A167743 A020888 A196393 * A357409 A086335 A123387

Adjacent sequences: A274086 A274087 A274088 * A274090 A274091 A274092

Keyword

nonn,easy

Author

N. J. A. Sloane, Jun 10 2016

Status

approved