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A086381 Numbers n such that p=n^2+2 and p+2 are primes. 11
1, 3, 15, 33, 45, 57, 117, 147, 243, 255, 303, 375, 423, 447, 453, 477, 573, 753, 837, 897, 903, 1035, 1497, 1905, 2055, 2085, 2193, 2283, 2433, 2487, 2535, 2583, 2757, 2823, 2943, 2955, 3003, 3213, 3285, 3345, 3603, 3657, 3687, 4407, 4575, 4977, 5037, 5043, 5325, 5355, 5367, 5403, 5727 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
The twin primes are given by A253639 and A085554. Except for the initial term, all a(n)=3 (mod 6). - M. F. Hasler, Jan 16 2015
LINKS
FORMULA
Intersection of A067201 and A007591. - M. F. Hasler, Jan 19 2015
PROG
(Magma)[n: n in [0..10000]|IsPrime(n^2+2) and IsPrime(n^2+4)] // Vincenzo Librandi, Dec 16 2010
(PARI) is_A086381(x)=ispseudoprime(x^2+2)&&ispseudoprime(x^2+4)
forstep(x=1, 9999, 2, is_A086381(x)&&print1(x", ")) \\ M. F. Hasler, Jan 16 2015
CROSSREFS
Sequence in context: A358804 A152813 A184235 * A031091 A211441 A086380
KEYWORD
easy,nonn
AUTHOR
Zak Seidov, Sep 07 2003
EXTENSIONS
More terms from Vincenzo Librandi, Dec 16 2010
STATUS
approved

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Last modified February 26 13:34 EST 2024. Contains 370352 sequences. (Running on oeis4.)