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

Author

N. J. A. Sloane, Jun 10 2016

Keywords

• nonn
• easy

Crossrefs

Cf. A057716.

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

Programs

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<>1 # Chai Wah Wu, Sep 05 2024

Formula

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