|
| |
|
|
A118016
|
|
Integers of the form 2^n/(n-1).
|
|
0
| |
|
|
4, 4, 8, 64, 8192, 268435456, 576460752303423488, 5316911983139663491615228241121378304, 904625697166532776746648320380374280103671755200316906558262375061821325312
(list; graph; refs; listen; history; internal format)
|
|
|
|
OFFSET
| 2,1
|
|
|
COMMENTS
| Terms of this sequence are four times the numbers of De Bruijn's sequence: 2^(2^(n-1) - n) (A016031) a(n)=4*A016031 - Paolo P. Lava (paoloplava(AT)gmail.com), Nov 10 2006
|
|
|
EXAMPLE
| n=5 2^5/(5-1) = 32/4 = 8
n=17 2^17/(17-1) = 131072/16 = 8192
|
|
|
MAPLE
| P:=proc(n) local i, j; for i from 2 by 1 to n do j:=2^i/(i-1); if trunc(j)=j then print(j); fi; od; end: P(5000);
|
|
|
MATHEMATICA
| f[n_]:=2^n/n*2; Select[Table[f[n], {n, 4, 6!}], IntegerQ] [From Vladimir Orlovsky (4vladimir(AT)gmail.com), Dec 05 2009]
|
|
|
CROSSREFS
| Cf. A016031.
Sequence in context: A137717 A102369 A205971 * A201989 A071775 A134576
Adjacent sequences: A118013 A118014 A118015 * A118017 A118018 A118019
|
|
|
KEYWORD
| nonn
|
|
|
AUTHOR
| Paolo P. Lava & Giorgio Balzarotti (paoloplava(AT)gmail.com), May 11 2006
|
| |
|
|
