A000799 a(n) = floor(2^n / n).

2, 2, 2, 4, 6, 10, 18, 32, 56, 102, 186, 341, 630, 1170, 2184, 4096, 7710, 14563, 27594, 52428, 99864, 190650, 364722, 699050, 1342177, 2581110, 4971026, 9586980, 18512790, 35791394, 69273666, 134217728, 260301048, 505290270, 981706810, 1908874353

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• easy

References

• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..300

Crossrefs

Cf. A000801, A053638, A065482, A082482, A071354, A193359.

Programs

GAP

List([1..40],n->Int(2^n/n)); # Muniru A Asiru, Oct 20 2018

Magma

[2^n div n : n in [1..40]]; // Vincenzo Librandi, Oct 14 2018

Maple

seq(floor(2^n/n),n=1..40); # Muniru A Asiru, Oct 20 2018

Mathematica

Table[Quotient[2^n,n],{n,60}] (* Vladimir Joseph Stephan Orlovsky, May 07 2011 *)

PARI

a(n)=1<
				

Python

for n in range(1, 40): print(int(2**n / n), end=", ") # Stefano Spezia, Oct 20 2018

Formula

Sum_{n>=1} 1/a(n) = A193359. - Amiram Eldar, Apr 03 2021