OFFSET
1,1
COMMENTS
Primes of form pq+4 where p and q are consecutive primes are in A063442.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 1..1000
FORMULA
prime(a(n))*prime(a(n)+1)+4 = A063442(n). - Zak Seidov, Oct 03 2013
EXAMPLE
MATHEMATICA
Position[Times@@#+4&/@Partition[Prime[Range[800]], 2, 1], _?PrimeQ]//Flatten (* Harvey P. Dale, Jun 16 2017 *)
PROG
(PARI) isok(n) = isprime(prime(n)*prime(n+1)+4); \\ Michel Marcus, Oct 04 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 02 2002
EXTENSIONS
Edited according to personal communication of Michel Marcus by Zak Seidov, Oct 03 2013
STATUS
approved