|
|
A154525
|
|
Primes p such that lcm(1,2,3,...,p-2,p-1,p) + 1 is prime.
|
|
2
|
|
|
2, 3, 5, 7, 19, 31, 47, 89, 127, 139, 2251, 3271, 4253, 4373, 4549, 5449, 13331, 37123, 55291
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
|
|
MATHEMATICA
|
Select[Range[1000], PrimeQ[#] && PrimeQ[LCM@@Range[#]+1] &] (* Amiram Eldar, Nov 21 2018 *)
|
|
PROG
|
(PARI) isok(p) = isprime(p) && (isprime(lcm(vector(p, i, i)) + 1)); \\ Michel Marcus, Oct 26 2013, Feb 25 2014
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
|
|
EXTENSIONS
|
a(1)=2 inserted and a(8)-a(18) from Ray Chandler, Jan 16 2009
|
|
STATUS
|
approved
|
|
|
|