|
| |
|
|
A098028
|
|
Smallest prime p such that p-2 is a product of exactly n distinct primes.
|
|
1
|
|
|
|
5, 17, 107, 1367, 15017, 285287, 6561557, 179444267, 3234846617, 100280245067, 3710369067407, 196649560572467, 8309321386330967, 307444891294245707, 24615215445537161447, 961380175077106319537, 78523577350789412776937
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
|
OFFSET
|
1,1
|
|
|
LINKS
|
Table of n, a(n) for n=1..17.
|
|
|
EXAMPLE
|
1367 is the 4th term in the sequence because it is followed by primes 1997, 2417, 3137, 3257, ... with the property 1367-2 = 3*5*7*13, 1997-2 = 3*5*7*19, 2417-2 = 3*5*7*23, 3137-2 = 3*5*11*19, 3257-2 = 3*5*7*31, ...
|
|
|
MATHEMATICA
|
Do[s = 3; While[ ! (Length[FactorInteger[Prime[s] - 2]] == n && Max[Last /@ FactorInteger[Prime[s] - 2]] == 1), s++ ]; Print[Prime[s]], {n, 1, 8}] (* Ryan Propper, Sep 01 2005 *)
With[{pn=PrimeNu[Prime[Range[11*10^6]]-2]}, Prime[#]&/@Flatten[Table[ Position[ pn, n, {1}, 1], {n, 8}]]] (* The program takes some time to generate the first 8 terms of the sequence *) (* Harvey P. Dale, Jan 18 2016 *)
|
|
|
CROSSREFS
|
Sequence in context: A297476 A235871 A240803 * A100301 A084167 A267143
Adjacent sequences: A098025 A098026 A098027 * A098029 A098030 A098031
|
|
|
KEYWORD
|
nonn,hard
|
|
|
AUTHOR
|
Lekraj Beedassy, Sep 10 2004
|
|
|
EXTENSIONS
|
Extended by Ray Chandler, Sep 18 2004
One more term from Ryan Propper, Sep 01 2005
More terms from Don Reble, Apr 03 2006
|
|
|
STATUS
|
approved
|
| |
|
|
