A124670 (Product of successive primes minus 2) divided by 3 is prime.

11, 47, 73, 107, 587, 673, 3467, 3673, 4783, 7499, 10799, 17327, 29983, 33073, 62207, 71147, 72073, 137387, 225227, 243673, 252283, 355007, 442367, 504299, 554699, 567673, 735073, 874799, 924073, 961067, 1062073, 1175627, 1326673, 1486847

Offset

1,1

Links

Harvey P. Dale, Table of n, a(n) for n = 1..1000

Example

11*13 = 143, 143-2 = 141, 141/3 = 47 is the second entry.

Mathematica

Select[(Times@@@Partition[Prime[Range[500]], 2, 1]-2)/3, PrimeQ] (* Harvey P. Dale, Oct 02 2012 *)

Prog

(PARI) g(n) = { for(x=1, n, y=prime(x)*prime(x+1)-2; if(y%3==0, if(isprime(y/3), print1(y/3", ")))) }

Crossrefs

Cf. A123921.

Sequence in context: A238665 A044113 A044494 * A142103 A031910 A009941

Adjacent sequences: A124667 A124668 A124669 * A124671 A124672 A124673

Keyword

easy,nonn

Author

Cino Hilliard, Dec 27 2006

Status

approved