A017912 Powers of sqrt(2) rounded up.

1, 2, 2, 3, 4, 6, 8, 12, 16, 23, 32, 46, 64, 91, 128, 182, 256, 363, 512, 725, 1024, 1449, 2048, 2897, 4096, 5793, 8192, 11586, 16384, 23171, 32768, 46341, 65536, 92682, 131072, 185364, 262144, 370728, 524288, 741456, 1048576, 1482911, 2097152, 2965821, 4194304

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn
• easy

Links

• Vincenzo Librandi, Table of n, a(n) for n = 0..1000

Crossrefs

Cf. A017910, A329202.

Programs

Magma

[Ceiling(Sqrt(2^n)): n in [0..40]]; // Vincenzo Librandi, Nov 20 2011

Mathematica

Ceiling[(Sqrt[2])^Range[0,40]] (* Vincenzo Librandi, Nov 20 2011 *)

Python

from math import isqrt
def A017912(n): return isqrt(1<>1) # Chai Wah Wu, Jul 26 2022

Formula

a(n) = A003059(A000079(n)). - Jason Kimberley, Oct 28 2016

a(n) = A017910(n)+1 if n is odd. a(n) = A017910(n) = 2^(n/2) if n is even. - Chai Wah Wu, Jul 26 2022