A234502 Primes of the form (p*q*r*s + 1)/2, where p, q, r, s are distinct primes.

683, 1523, 2153, 2243, 2393, 2423, 2503, 2657, 3023, 3203, 3581, 3833, 4133, 4373, 4583, 4673, 4967, 5003, 5051, 5233, 5273, 5303, 5483, 5653, 5843, 6221, 6299, 6793, 7193, 7211, 7487, 7523, 7703, 7823, 7937, 8093, 8243, 8543, 8693, 9323, 9377, 9461, 9533

Offset: 1

Author

Clark Kimberling, Jan 01 2014

Keywords

• nonn
• easy

Examples

			(See A234501.)
		

Crossrefs

Cf. A234500, A234501, A234499, A234104.

Programs

Mathematica

t = Select[Range[1, 20000, 2], Map[Last, FactorInteger[#]] == Table[1, {4}] &]; Take[(t + 1)/2, 120] (* A234500 *)
v = Flatten[Position[PrimeQ[(t + 1)/2], True]] ; w = Table[t[[v[[n]]]], {n, 1, Length[v]}]  (* A234501 *)
(w + 1)/2 (* A234502 *)   (* Peter J. C. Moses, Dec 23 2013 *)