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Prime numbers n such that n^2 +- (n-1) are primes.
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%I #8 Jul 15 2023 15:55:07

%S 2,3,13,163,193,349,541,769,1093,1231,1423,1549,1621,1693,1801,2011,

%T 3049,3511,4003,4111,4159,5839,6091,6421,6703,6883,7573,7753,8929,

%U 9043,9601,9769,9781,12781,13633,14821,15091,15439,16141,16759,17863,18493

%N Prime numbers n such that n^2 +- (n-1) are primes.

%H Vincenzo Librandi, <a href="/A137459/b137459.txt">Table of n, a(n) for n = 1..1000</a>

%e 2^2 +- 1 -> (3,4) Primes,

%e 3^2 +- 2 -> (7,11) Primes,

%e 13^2 +- 12 -> (157,181) Prime

%t Select[Prime[Range[800]],PrimeQ[ #^2-(#-1)]&&PrimeQ[ #^2+(#-1)]&]

%t Select[Prime[Range[2500]],AllTrue[#^2+{(#-1),(1-#)},PrimeQ]&] (* _Harvey P. Dale_, Jul 15 2023 *)

%K nonn,easy

%O 1,1

%A _Vladimir Joseph Stephan Orlovsky_, Apr 21 2008

%E More terms from _Stefan Steinerberger_, Apr 26 2008