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 A124670 (Product of successive primes minus 2) divided by 3 is prime. 1

%I

%S 11,47,73,107,587,673,3467,3673,4783,7499,10799,17327,29983,33073,

%T 62207,71147,72073,137387,225227,243673,252283,355007,442367,504299,

%U 554699,567673,735073,874799,924073,961067,1062073,1175627,1326673,1486847

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

%H Harvey P. Dale, <a href="/A124670/b124670.txt">Table of n, a(n) for n = 1..1000</a>

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

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

%o (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",")))) }

%Y Cf. A123921.

%K easy,nonn

%O 1,1

%A _Cino Hilliard_, Dec 27 2006

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Last modified April 2 00:42 EDT 2023. Contains 361723 sequences. (Running on oeis4.)