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%I #19 Sep 08 2022 08:45:28
%S 1,2,5,7,37,47,65,67,73,80,115,128,163,170,175,203,215,220,235,292,
%T 317,343,350,352,392,430,460,493,527,535,578,605,662,670,677,683,697,
%U 710,728,730,782,850,892,908,938,1003,1040,1048,1087,1235,1267,1285,1300
%N Numbers n such that (2*n)^2 + 1 and (2*n)^2 + 3 are both prime.
%H Harvey P. Dale, <a href="/A123232/b123232.txt">Table of n, a(n) for n = 1..1000</a>
%e a(4) = 7 because 14^2 + 1 = 197 and 14^2 + 3 = 199 which are both prime.
%p for i from 1 to 1000 do if(isprime(i^2 +1) and isprime(i^2+3)) then print(i/2); end if; end do;
%t Select[Range[1300],AllTrue[(2#)^2+{1,3},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Jan 15 2016 *)
%o (Magma) [n: n in [0..6000] | IsPrime((2*n)^2+1)and IsPrime((2*n)^2+3)] // _Vincenzo Librandi_, Nov 13 2010
%Y Cf. A001359.
%K nonn
%O 1,2
%A _Ben Paul Thurston_, Oct 06 2006
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