A141893 - OEIS

%I #20 Sep 08 2022 08:45:35

%S 11,53,137,179,263,347,389,431,557,599,641,683,809,977,1019,1061,1103,

%T 1187,1229,1439,1481,1523,1607,1733,1901,2027,2069,2111,2153,2237,

%U 2447,2531,2657,2699,2741,2909,3119,3203,3329,3371,3413,3539,3581,3623,3833,3917

%N Primes congruent to 11 mod 21.

%H Vincenzo Librandi, <a href="/A141893/b141893.txt">Table of n, a(n) for n = 1..1000</a>

%F a(n) ~ 12n log n. - _Charles R Greathouse IV_, Jul 02 2016

%t Select[Range[11,5000,21],PrimeQ] (* _Vladimir Joseph Stephan Orlovsky_, Apr 04 2011 *)

%o (Magma) [ p: p in PrimesUpTo(5000) | p mod 21 eq 11 ]; // _Vincenzo Librandi_, Apr 05 2011

%o (PARI) is(n)=isprime(n) && n%21==11 \\ _Charles R Greathouse IV_, Jul 02 2016

%Y Cf. A000040, A124826.

%K nonn,easy

%O 1,1

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