A094386 a(n) = floor(sqrt(3)*2^(n-1)).

1, 3, 6, 13, 27, 55, 110, 221, 443, 886, 1773, 3547, 7094, 14188, 28377, 56755, 113511, 227023, 454046, 908093, 1816186, 3632373, 7264747, 14529495, 29058990, 58117981, 116235962, 232471924, 464943848, 929887696, 1859775393, 3719550786

Offset: 1

Author

Roger L. Bagula, Jun 03 2004

Keywords

• nonn

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Programs

Magma

[Floor(2^(n-1)*Sqrt(3)): n in [1..40]]; // Vincenzo Librandi, Sep 20 2017

Mathematica

Table[Floor[Sqrt[3] 2^(n-1)], {n, 40}] (* Vincenzo Librandi, Sep 20 2017 *)

PARI

a(n) = floor(sqrt(3)*2^(n-1)); \\ Michel Marcus, Sep 20 2017

Python

from math import isqrt
def A094386(n): return isqrt(3*(1<<(n-1<<1))) # Chai Wah Wu, Jul 28 2022

Formula

a(n) = A022838(2^(n-1)). - R. J. Mathar, Oct 22 2011