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A210362
Prime numbers p such that x^2 + x + p produces primes for x = 0..3 but not x = 4.
7
5, 101, 227, 1091, 1481, 1487, 3917, 4127, 4787, 8231, 9461, 10331, 11777, 12107, 14627, 16061, 20747, 25577, 27737, 29021, 32297, 33347, 35531, 35591, 36467, 38447, 39227, 41177, 42461, 44267, 44531, 49031, 59441, 69191, 77237, 79811, 80777, 93251, 93491
OFFSET
1,1
COMMENTS
The first term is A164926(4).
MATHEMATICA
lookfor = 4; t = {}; n = 0; While[Length[t] < 50, n++; c = Prime[n]; i = 1; While[PrimeQ[i^2 + i + c], i++]; If[i == lookfor, AppendTo[t, c]]]; t
Select[Prime[Range[10000]], AllTrue[#+{2, 6, 12}, PrimeQ]&&!PrimeQ[#+20]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 26 2015 *)
Select[Prime[Range[10000]], Boole[PrimeQ[#+{2, 6, 12, 20}]]=={1, 1, 1, 0}&] (* Harvey P. Dale, Nov 17 2024 *)
KEYWORD
nonn,changed
AUTHOR
T. D. Noe, Apr 05 2012
STATUS
approved