

A086086


Primes p such that p  floor(sqrt(p)) is prime.


6



3, 5, 7, 17, 23, 37, 43, 47, 67, 79, 107, 113, 149, 151, 163, 211, 257, 331, 349, 409, 421, 439, 509, 521, 587, 593, 601, 617, 709, 727, 797, 839, 907, 911, 937, 941, 1051, 1063, 1163, 1187, 1319, 1327, 1447, 1471, 1489, 1607, 1619, 1637, 1667, 1783, 1789, 1801
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OFFSET

1,1


LINKS



EXAMPLE

a(5)=23 because 19 is prime and 23  (floor(Sqrt(23)) = 23  (floor(4.795831523)) = 23  4 = 19, which is prime.


MATHEMATICA

Select[Prime[Range[300]], PrimeQ[#Floor[Sqrt[#]]]&] (* Harvey P. Dale, Sep 26 2017 *)


CROSSREFS



KEYWORD

nonn


AUTHOR

Chuck Seggelin (barkeep(AT)plastereddragon.com), Jul 08 2003


EXTENSIONS



STATUS

approved



