A272629 Primes p such that (p^2 + p + 1)/13 is prime.
29, 113, 419, 503, 659, 887, 1277, 1361, 1433, 2141, 2213, 2687, 3851, 4007, 4397, 4787, 5333, 5417, 5573, 7127, 7757, 7829, 8609, 8693, 8849, 9161, 9311, 9623, 10247, 10487, 11261, 11423, 12197, 12743, 13217, 13523, 14537, 14621, 14771, 15083, 15161
Offset: 1
Keywords
Examples
a(1) = 29 because (29^2+29+1)/13 = 67 is a prime.
Links
- Seiichi Manyama, Table of n, a(n) for n = 1..1000
Crossrefs
Cf. A002642.
Programs
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Mathematica
Select[Prime[Range[5000]], PrimeQ[(#^2 + # + 1) / 13] &]
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PARI
lista(nn) = {forprime(p=2, nn, if ((denominator(q=(p^2 + p + 1)/13)== 1) && isprime(q), print1(p, ", ")););} \\ Michel Marcus, May 05 2016
Comments