

A104163


Primes p such that (2p+1)/3 is prime.


5



7, 19, 43, 61, 79, 109, 151, 163, 223, 271, 349, 421, 439, 523, 601, 613, 631, 673, 691, 811, 853, 919, 991, 1009, 1051, 1063, 1153, 1213, 1231, 1279, 1321, 1429, 1531, 1549, 1663, 1693, 1789, 1801, 1873, 1933, 1951, 2113, 2143, 2179, 2221, 2239, 2503, 2539
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OFFSET

1,1


COMMENTS



LINKS



FORMULA



EXAMPLE

7 is in the sequence because (2 * 7 + 1)/3 = 5, which is also prime.
19 is in the sequence because (2 * 19 + 1)/3 = 13, which is also prime.


MATHEMATICA

Select[Range[7, 2539, 2], PrimeQ[#] && PrimeQ[(2# + 1)/3]&] (* Zak Seidov, Jul 31 2012 *)
Select[Prime[Range[400]], PrimeQ[(2 # + 1) / 3]&] (* Vincenzo Librandi, Apr 14 2013 *)


PROG



CROSSREFS



KEYWORD

nonn,easy


AUTHOR



EXTENSIONS



STATUS

approved



