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%I #11 Sep 08 2022 08:45:32
%S 181,1621,6481,8821,35281,52021,58321,87121,103681,112501,131221,
%T 141121,151381,172981,184321,302581,380881,414721,450001,486721,
%U 544501,626581,691921,737281,784081,808021,1039681,1067221,1240021,1300501,1362421
%N Primes of the form 5k^2 + 1.
%C All k are multiples of 6, k=6j, where j are numbers in A138218.
%t Select[5*Range[600]^2+1,PrimeQ] (* _Harvey P. Dale_, Dec 06 2015 *)
%o (Magma)[a: n in [0..1000]|IsPrime(a) where a is 1+5*n^2] // _Vincenzo Librandi_, Dec 13 2010
%K nonn
%O 1,1
%A _Zak Seidov_, Apr 27 2008