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Numbers n such that 23*n^2 - 36 is prime.
1

%I #17 Sep 08 2022 08:45:20

%S 1,7,13,31,43,55,97,101,113,119,133,139,151,161,167,185,199,211,221,

%T 227,239,265,277,283,295,305,323,353,371,385,403,407,427,451,461,463,

%U 475,515,517,539,557,559,581,613,617,641,661,685,689,697,713,767,769,773

%N Numbers n such that 23*n^2 - 36 is prime.

%H G. C. Greubel, <a href="/A110912/b110912.txt">Table of n, a(n) for n = 1..5000</a>

%e If n=133 then 23*n^2 - 36 = 406811 (prime).

%t Select[Range[800], PrimeQ[23*#^2 - 36] &] (* _Stefan Steinerberger_, Feb 28 2006 *)

%o (Magma) [n: n in [0..1000]| IsPrime(23*n^2- 36)]; // _Vincenzo Librandi_, Feb 03 2011

%o (PARI) is(n)=isprime(23*n^2-36) \\ _Charles R Greathouse IV_, Jun 13 2017

%K nonn,easy

%O 1,2

%A _Parthasarathy Nambi_, Oct 03 2005

%E More terms from _Stefan Steinerberger_, Feb 28 2006