A175284 - OEIS

A175284

Primes p of the form p=n^2+3n+9 such that q=p^2+3p+9 is also prime.

7, 37, 163, 709, 877, 46447, 67867, 81517, 118687, 238639, 292147, 331207, 430999, 497737, 548347, 628063, 1120429, 1412539, 1462897, 1655089, 1680919, 1955809, 2642257, 3205897, 3358063, 3394813, 3781087, 4654813, 4715419, 4745869

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OFFSET

1,1

COMMENTS

Intersection of A175283 and A005471.

LINKS

Table of n, a(n) for n=1..30.

MATHEMATICA

Reap[Do[If[PrimeQ[p=n^2+3n+9]&&PrimeQ[q=p^2+3p+9], Sow[p]], {n, -1, 10^4}]][[2, 1]]

CROSSREFS

Cf. A005471, A175281-3.

Sequence in context: A269257 A269258 A247308 * A049494 A049495 A169789

Adjacent sequences: A175281 A175282 A175283 * A175285 A175286 A175287

KEYWORD

nonn

AUTHOR

Zak Seidov, Mar 21 2010

STATUS

approved