|
|
A049613
|
|
a(n) = 2n - (largest prime < 2n-2).
|
|
6
|
|
|
3, 3, 3, 5, 3, 3, 5, 3, 3, 5, 3, 5, 7, 3, 3, 5, 7, 3, 5, 3, 3, 5, 3, 5, 7, 3, 5, 7, 3, 3, 5, 7, 3, 5, 3, 3, 5, 7, 3, 5, 3, 5, 7, 3, 5, 7, 9, 3, 5, 3, 3, 5, 3, 3, 5, 3, 5, 7, 9, 11, 13, 15, 3, 5, 3, 5, 7, 3, 3, 5, 7, 9, 11, 3, 3, 5, 7, 3, 5, 7, 3, 5, 3, 5, 7, 3, 5, 7, 3, 3, 5
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
3,1
|
|
LINKS
|
|
|
FORMULA
|
|
|
EXAMPLE
|
a(14)=28 - (largest prime < 26) = 28 - 23 = 5.
|
|
MATHEMATICA
|
Table[2n-NextPrime[2n-2, -1], {n, 3, 100}] (* Harvey P. Dale, Aug 16 2011 *)
|
|
PROG
|
(Haskell)
a049613 n = 2 * n - a007917 (2 * n - 2)
|
|
CROSSREFS
|
|
|
KEYWORD
|
nice,nonn,easy
|
|
AUTHOR
|
David M. Elder (elddm(AT)rhodes.edu)
|
|
STATUS
|
approved
|
|
|
|