OFFSET
1,1
COMMENTS
prime(i)*prime(i+1) + prime(i+2) + 1 is prime.
In the sequence there are some twins: e.g. (281, 283) and (1949, 1951).
There are also successive primes such as (13,17,19); (277,281,283,293,307); (883,887).
EXAMPLE
a(5)=19 since 19*23+29+1=467 is a prime.
MATHEMATICA
#[[1]]&/@Select[Partition[Prime[Range[200]], 3, 1], PrimeQ[ #[[1]] #[[2]]+#[[3]]+1]&] (* Harvey P. Dale, Nov 07 2010 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Carmine Suriano, Sep 27 2010
EXTENSIONS
Missing values starting at 1031 inserted by R. J. Mathar, Oct 18 2010
STATUS
approved