A210362 Prime numbers p such that x^2 + x + p produces primes for x = 0..3 but not x = 4.
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
Keywords
Links
- T. D. Noe, Table of n, a(n) for n = 1..1000
Programs
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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 *)
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