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A173826 Primes p such that p-+floor(Sqrt(p)) are primes. 2
5, 37, 47, 151, 331, 349, 593, 617, 907, 911, 937, 941, 1789, 1831, 2341, 2389, 2399, 2957, 3617, 3631, 3673, 3719, 4457, 5261, 5309, 6121, 6151, 6199, 6221, 7103, 7127, 7213, 8101, 8179, 9323, 9337, 9377, 10529, 10589, 11789, 13007, 13033, 13037 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

5-+2->primes, 37-+6->primes,..

LINKS

Table of n, a(n) for n=1..43.

MATHEMATICA

f1[n_]:=n-Floor[Sqrt[n]]; f2[n_]:=n+Floor[Sqrt[n]]; lst={}; Do[p=Prime[n]; If[PrimeQ[f1[p]]&&PrimeQ[f2[p]], AppendTo[lst, p]], {n, 8!}]; lst

CROSSREFS

Cf. A086085, A086086

Sequence in context: A106129 A096673 A144960 * A071680 A141182 A127589

Adjacent sequences:  A173823 A173824 A173825 * A173827 A173828 A173829

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, Feb 25 2010

STATUS

approved

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Last modified June 1 02:09 EDT 2020. Contains 334758 sequences. (Running on oeis4.)