A144620 Numbers k such that k and 19*k + 8 are both prime.

5, 17, 41, 59, 89, 167, 191, 239, 269, 281, 359, 449, 479, 491, 509, 521, 587, 617, 647, 701, 719, 821, 881, 911, 929, 971, 1031, 1181, 1217, 1259, 1289, 1307, 1361, 1367, 1559, 1601, 1697, 1709, 1721, 1787, 1877, 1889, 1907, 1931, 1949, 1997, 2039, 2129

Offset

1,1

Links

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

Example

For n=5, 19*5 + 8 = 103;
for n=269, 19*269 + 8 = 5119.

Maple

a := proc (n) if isprime(n) = true and isprime(19*n+8) = true then n else end if end proc: seq(a(n), n = 1 .. 2300); # Emeric Deutsch, Jan 27 2009

Mathematica

Select[Prime[Range[400]], PrimeQ[#] &&PrimeQ[19#+8] &] (* Vincenzo Librandi, Aug 30 2012 *)

Prog

(Magma) [p: p in PrimesUpTo(2500)|IsPrime(19*p+8)] // Vincenzo Librandi, Aug 30 2012

Crossrefs

Cf. A141873, A144619.

Sequence in context: A332689 A342320 A341759 * A217622 A269728 A091864

Adjacent sequences: A144617 A144618 A144619 * A144621 A144622 A144623

Keyword

nonn,easy

Author

Vincenzo Librandi, Jan 15 2009

Extensions

Extended by Emeric Deutsch, Jan 27 2009

Status

approved