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Primes of the form p*q*r + 2, where p, q and r are distinct primes.
0

%I #6 May 01 2012 19:48:40

%S 107,167,197,233,257,347,359,401,431,457,467,557,563,617,647,653,743,

%T 761,797,863,887,937,971,1087,1097,1187,1223,1237,1283,1297,1409,1481,

%U 1493,1549,1553,1583,1597,1601,1607,1637,1697,1871,1889,1907,1949,2003,2017

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

%F {A007304(n)+2} INTERSECTION {A000040}.

%e 107 = 3*5*7+2.

%t mx = 50; ps = Prime[Range[2, mx + 1]]; t = Table[ps[[i]]*ps[[j]]*ps[[k]] + 2, {i, mx}, {j, i + 1, mx}, {k, j + 1, mx}]; Select[Union[Flatten[t]], # <= 3*5*ps[[-1]] + 2 && PrimeQ[#] &] (* _T. D. Noe_, May 01 2012 *)

%Y Cf. A115267.

%K nonn

%O 1,1

%A _Alex Ratushnyak_, May 01 2012