

A236458


Primes p with p + 2 and prime(p) + 2 both prime.


16



3, 5, 17, 41, 1949, 2309, 2711, 2789, 2801, 3299, 3329, 3359, 3917, 4157, 4217, 4259, 4637, 5009, 5021, 5231, 6449, 7757, 8087, 8219, 8627, 9419, 9929, 10007, 10937, 11777, 12071, 14321, 15647, 15971, 16061, 16901, 18131, 18251, 18287, 18539
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OFFSET

1,1


COMMENTS

According to the conjecture in A236470, the sequence should have infinitely many terms. This is stronger than the twin prime conjecture.


LINKS



EXAMPLE

a(1) = 3 since 3 + 2 = 5 and prime(3) + 2 = 7 are both prime, but 2 + 2 = 4 is composite.


MATHEMATICA

p[n_]:=PrimeQ[n+2]&&PrimeQ[Prime[n]+2]
n=0; Do[If[p[Prime[m]], n=n+1; Print[n, " ", Prime[m]]], {m, 1, 10000}]


PROG

(PARI) s=[]; forprime(p=2, 20000, if(isprime(p+2) && isprime(prime(p)+2), s=concat(s, p))); s \\ Colin Barker, Jan 26 2014


CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



