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Primes congruent to 1 mod 55.
1

%I #9 Sep 08 2022 08:45:36

%S 331,661,881,991,1321,1871,2311,2531,2861,2971,3191,3301,3631,3851,

%T 4621,4951,5171,5281,5501,6271,6491,7151,7481,7591,8581,9241,9461,

%U 9791,9901,10781,10891,11551,12101,12211,12541,13421,13751,14081,14411,14741,14851

%N Primes congruent to 1 mod 55.

%H Vincenzo Librandi, <a href="/A142601/b142601.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) ~ 40n log n. - _Charles R Greathouse IV_, Jul 04 2016

%t Select[Prime[Range[2500]], MemberQ[{1}, Mod[#, 55]] &] (* _Vincenzo Librandi_, Aug 30 2012 *)

%o (Magma) [p: p in PrimesUpTo(16000) | p mod 55 eq 1]; // _Vincenzo Librandi_, Aug 30 2012

%o (PARI) is(n)=isprime(n) && n%55==1 \\ _Charles R Greathouse IV_, Jul 04 2016

%Y Cf. A000040.

%K nonn,easy

%O 1,1

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