A141882 Primes congruent to 7 mod 20.

7, 47, 67, 107, 127, 167, 227, 307, 347, 367, 467, 487, 547, 587, 607, 647, 727, 787, 827, 887, 907, 947, 967, 1087, 1187, 1307, 1327, 1367, 1427, 1447, 1487, 1567, 1607, 1627, 1667, 1747, 1787, 1847, 1867, 1907, 1987, 2027, 2087, 2207, 2267, 2287, 2347, 2447

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..1000

Mathematica

Select[Range[7, 5000, 20], PrimeQ[#]&] (* Vladimir Joseph Stephan Orlovsky, Mar 31 2011*)
Select[Prime[Range[400]], Mod[#, 20]==7&] (* Harvey P. Dale, Jan 08 2023 *)

Prog

(Magma) [p: p in PrimesUpTo(3000) | p mod 20 eq 7 ]; // Vincenzo Librandi, Aug 16 2012
(PARI) is(n)=isprime(n) && n%20==7 \\ Charles R Greathouse IV, Jul 01 2016

Crossrefs

Cf. A000040, A105854, A141881, A141883.

Sequence in context: A122731 A059452 A245229 * A240569 A261183 A067658

Adjacent sequences: A141879 A141880 A141881 * A141883 A141884 A141885

Keyword

nonn,easy

Author

N. J. A. Sloane, Jul 11 2008

Status

approved