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A127845
Numbers k such that k^2 + 5 and k^2 + 7 are twin primes.
1
0, 6, 12, 36, 48, 78, 114, 162, 258, 414, 666, 792, 804, 996, 1044, 1206, 1308, 1314, 1356, 1548, 1584, 1632, 1734, 1902, 2106, 2196, 2214, 2346, 2358, 2592, 2634, 2766, 2808, 2868, 2892, 2988, 3072, 3246, 3432, 3516, 3576, 3774, 3894, 3912, 3996, 4038
OFFSET
1,2
COMMENTS
All terms are multiples of 6. Intersection of A114270 and A078402.
LINKS
MAPLE
filter:= n -> isprime(n^2+5) and isprime(n^2+7):
N:= 10000: # to get all entries <= 6*N
A127845:= select(filter, [6*n $ n=0..N]); # Robert Israel, Apr 17 2014
MATHEMATICA
Select[Range[0, 5000, 6], AllTrue[#^2+{5, 7}, PrimeQ]&] (* Harvey P. Dale, May 25 2023 *)
PROG
(Magma) [n: n in [0..500] | IsPrime(n^2+5) and IsPrime(n^2+7)] // Vincenzo Librandi, Nov 23 2010
CROSSREFS
Sequence in context: A166636 A167338 A078402 * A306899 A096932 A376003
KEYWORD
nonn
AUTHOR
Zak Seidov, Apr 05 2007
STATUS
approved