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A175284 Primes p of the form p=n^2+3n+9 such that q=p^2+3p+9 is also prime. 1
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 (list; graph; refs; listen; history; text; internal format)
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

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Last modified July 9 04:51 EDT 2020. Contains 335538 sequences. (Running on oeis4.)