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A283867 Numbers n such that 30*n^2 - 1 and 30*n^2 + 1 are (twin) primes.

%I A283867 #23 Sep 08 2022 08:46:19
%S A283867 1,3,10,14,18,38,62,73,116,118,143,183,221,232,242,330,333,413,430,
%T A283867 455,470,496,507,533,538,556,606,622,645,675,687,701,720,777,792,819,
%U A283867 846,879,881,895,913,1000,1019,1030,1092,1155,1214,1238,1253,1261,1313,1337,1350,1407,1418,1429,1431
%N A283867 Numbers n such that 30*n^2 - 1 and 30*n^2 + 1 are (twin) primes.
%H A283867 Charles R Greathouse IV, <a href="/A283867/b283867.txt">Table of n, a(n) for n = 1..10000</a>
%F A283867 a(n) >> n log^2 n. - _Charles R Greathouse IV_, Mar 17 2017
%e A283867 3 is in this sequence because 30*3^2 - 1 = 269 and 30*3^2 + 1 = 271 are twin primes.
%t A283867 Select[Range@ 1431, PrimeQ[30*#^2 + 1] && PrimeQ[30*#^2 - 1] &] (* _Indranil Ghosh_, Mar 17 2017 *)
%o A283867 (Magma) [n: n in [1..1500] | IsPrime(30*n^2-1) and IsPrime(30*n^2+1)];
%o A283867 (PARI) is(n)=isprime(30*n^2-1) && isprime(30*n^2+1) \\ _Charles R Greathouse IV_, Mar 17 2017
%o A283867 (Python)
%o A283867 from sympy import isprime
%o A283867 [i for i in range(1, 1501) if isprime(30*i**2 - 1) and isprime(30*i**2 + 1)] # _Indranil Ghosh_, Mar 17 2017
%Y A283867 Cf. A000290, A001097, A077800, A158558, A158560.
%K A283867 nonn
%O A283867 1,2
%A A283867 _Juri-Stepan Gerasimov_, Mar 17 2017