A087745 Numbers A001317 repeated.

1, 1, 3, 3, 5, 5, 15, 15, 17, 17, 51, 51, 85, 85, 255, 255, 257, 257, 771, 771, 1285, 1285, 3855, 3855, 4369, 4369, 13107, 13107, 21845, 21845, 65535, 65535, 65537, 65537, 196611, 196611, 327685, 327685, 983055, 983055, 1114129, 1114129

Offset: 0

Author

Philippe Deléham, Oct 02 2003

Keywords

• easy
• nonn

Comments

Triangles A049444, A049459, A051338, A051379, A051523 (Mitrinovic's triangles) mod 2 converted to decimal.

Sequence [1, 3, 5, 15, 17, 51, 85, 255, 257, ...] = A001317.

Crossrefs

Cf. A001317, A049444, A049459, A051338, A051378, A051523.

Programs

Python

def A087745(n): return sum((bool(~(m:=n>>1)&m-k)^1)<>1)+1)) # Chai Wah Wu, May 02 2023

Extensions

Definition corrected and edited by Omar E. Pol, Dec 24 2008