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A260555 Primes p such that p = q^2 + 6*r^2 where q and r are also primes. 5
73, 79, 103, 193, 199, 223, 271, 313, 439, 463, 751, 823, 991, 1039, 1063, 1087, 1303, 1423, 1543, 1567, 1663, 1759, 1783, 1831, 1873, 1999, 2143, 2287, 2383, 2503, 2833, 3343, 3463, 3583, 3631, 3823, 3847, 3943, 4447, 4513, 4639, 4783, 5023, 5167, 5407 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
LINKS
EXAMPLE
73 is in the sequence because 73 = 7^2 + 6*2^2 and 73, 7 and 2 are all primes.
MATHEMATICA
Select[#1^2 + 6 #2^2 & @@ # & /@ Tuples[Prime@ Range@ 60, 2], PrimeQ] // Sort (* Michael De Vlieger, Jul 29 2015 *)
CROSSREFS
Sequence in context: A153646 A179516 A180558 * A345550 A345804 A064667
KEYWORD
nonn
AUTHOR
Colin Barker, Jul 29 2015
STATUS
approved

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Last modified March 28 04:05 EDT 2024. Contains 371235 sequences. (Running on oeis4.)