A240596 - OEIS

%I #14 Nov 21 2018 18:08:34

%S 107,4201,18181981,29884303,72147193,81927499,208506511,383148631,

%T 402473443,1106558899,1391119621,1459314919,1498299289,1945171369,

%U 4593570199,7908301729,8052037969,9970592521,10594343761,11304695329,14119758703,15111907009,23157107803

%N Primes of the form p*q*r + 2 where p, q and r are consecutive primes.

%C All the terms in the sequence, except a(1), are congruent to 1 mod 6.

%H K. D. Bajpai, <a href="/A240596/b240596.txt">Table of n, a(n) for n = 1..3525</a>

%e 107 is prime and appears in the sequence because 107 = (3*5*7)+2.

%e 4201 is prime and appears in the sequence because 4201 = (13*17*19)+2.

%p KD := proc() local a, b; a:=ithprime(n)*ithprime(n+1)*ithprime(n+2); b:=a+2; if isprime(b) then RETURN (b); fi; end: seq(KD(), n=1..1000);

%t Select[Table[Prime[k]*Prime[k+1]*Prime[k+2]+2,{k,1,300}],PrimeQ]

%t Select[Times@@@Partition[Prime[Range[600]],3,1]+2,PrimeQ] (* _Harvey P. Dale_, Nov 21 2018 *)

%o (PARI) s=[]; for(k=1, 1000, t=prime(k)*prime(k+1)*prime(k+2)+2; if(isprime(t), s=concat(s, t))); s \\ _Colin Barker_, Apr 09 2014

%Y Cf. A000040, A048880, A051507.

%K nonn

%O 1,1

%A _K. D. Bajpai_, Apr 08 2014