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A124826
Primes congruent to 1 mod 21.
16
43, 127, 211, 337, 379, 421, 463, 547, 631, 673, 757, 883, 967, 1009, 1051, 1093, 1303, 1429, 1471, 1597, 1723, 1933, 2017, 2143, 2269, 2311, 2437, 2521, 2647, 2689, 2731, 2857, 3067, 3109, 3319, 3361, 3529, 3571, 3613, 3697, 3739, 3823, 3907, 4159, 4201
OFFSET
1,1
LINKS
MATHEMATICA
Select[Range[1, 5000, 21], PrimeQ] (* Vladimir Joseph Stephan Orlovsky, Apr 03 2011*)
PROG
(Magma) [p: p in PrimesUpTo(5000) | p mod 21 eq 1 ]; // Vincenzo Librandi, Aug 14 2012
(PARI) is(n)=isprime(n) && n%21==1 \\ Charles R Greathouse IV, Jul 01 2016
CROSSREFS
Sequence in context: A044675 A112270 A356510 * A136069 A140028 A199818
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jul 11 2008
STATUS
approved