OFFSET
1,2
LINKS
Harry J. Smith, Table of n, a(n) for n = 1..1000
EXAMPLE
2*3*prime(3) + 1 = 2 * 3 * 5 + 1 = 31 a prime.
MAPLE
select(i->isprime(2*i*ithprime(i)+1), [$1..300]); # Muniru A Asiru, Jun 29 2018
MATHEMATICA
Select[Range[300], PrimeQ[2# Prime[#]+1]&] (* Harvey P. Dale, Sep 12 2014 *)
PROG
(PARI) select(k->isprime(2*k*prime(k)+1), [1..700])
(Magma) [n: n in [1..300] |IsPrime(2*n*NthPrime(n) + 1)]; // Vincenzo Librandi, Jun 29 2018
CROSSREFS
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 08 2001
STATUS
approved