OFFSET
1,1
COMMENTS
a(26) > 25000. - Robert Price, Sep 27 2017
EXAMPLE
3 is in the sequence because 3*5*7 - 2*11 = 83 is a prime.
MATHEMATICA
k = 1; a = {}; Do[k = k*Prime[n]; If[PrimeQ[k - 2*Prime[n + 1]], AppendTo[a, n - 1]], {n, 2, 2000}]; a
PROG
(PARI) isok(n) = isprime(prod(k=2, n+1, prime(k)) - 2*prime(n+2)); \\ Michel Marcus, Sep 27 2017
CROSSREFS
KEYWORD
nonn,more
AUTHOR
Artur Jasinski, Apr 22 2008
EXTENSIONS
Edited by Jens Kruse Andersen, May 03 2008
a(15)-a(25) from Robert Price, Sep 27 2017
STATUS
approved