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

1,1

Links

Table of n, a(n) for n=1..43.

Example

(See A234501.)

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 *)

Crossrefs

Cf. A234500, A234501, A234499, A234104.

Sequence in context: A320772 A045154 A300193 * A089201 A292174 A065123

Adjacent sequences: A234499 A234500 A234501 * A234503 A234504 A234505

Keyword

nonn,easy

Author

Clark Kimberling, Jan 01 2014

Status

approved