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Primes congruent to 1 mod 25.
3

%I #13 Sep 08 2022 08:45:35

%S 101,151,251,401,601,701,751,1051,1151,1201,1301,1451,1601,1801,1901,

%T 1951,2251,2351,2551,2801,2851,3001,3251,3301,3701,3851,4001,4051,

%U 4201,4451,4651,4751,4801,4951,5051,5101,5351,5501,5651,5701,5801,5851,6101,6151

%N Primes congruent to 1 mod 25.

%H Vincenzo Librandi, <a href="/A141927/b141927.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) ~ 20n log n. - _Charles R Greathouse IV_, Jul 02 2016

%t Select[Prime[Range[900]], MemberQ[{1}, Mod[#, 25]] &] (* _Vincenzo Librandi_, Aug 16 2012 *)

%t Select[Range[1,6200,25],PrimeQ] (* _Harvey P. Dale_, Oct 02 2016 *)

%o (Magma) [p: p in PrimesUpTo(8000) | p mod 25 eq 1 ]; // _Vincenzo Librandi_, Aug 16 2012

%o (PARI) is(n)=isprime(n) && n%25==1 \\ _Charles R Greathouse IV_, Jul 02 2016

%Y Cf. A000040.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_, Jul 11 2008