A123986 Numbers n for which 4n+1 and 4n+3 are primes.

1, 4, 7, 10, 25, 34, 37, 49, 67, 70, 115, 130, 142, 154, 160, 202, 205, 214, 220, 262, 265, 307, 319, 322, 325, 370, 424, 430, 469, 487, 499, 520, 532, 535, 559, 577, 595, 637, 664, 682, 697, 700, 742, 814, 832, 847, 865, 889, 895, 955, 979, 982, 1000, 1012, 1039

Offset

1,2

Comments

All terms == 1 mod 3. - Zak Seidov, Dec 02 2011

Intersection of A005098 and A095278. - Michel Marcus, Jan 31 2015

Links

Zak Seidov, Table of n, a(n) for n = 1..10000

Mathematica

Select[Range[1100], And @@ PrimeQ /@ ({1, 3} + 4#) &] (* Ray Chandler, Nov 05 2006 *)
nn=10000; k=0; x=1; re=Reap[While[k<nn-.1, If[PrimeQ[1+4x]&&PrimeQ[3+4x], Sow[x]; k++]; x=x+3]][[2, 1]] (* Zak Seidov, Dec 02 2011 *)

Prog

(Magma) [n: n in [0..1100] |IsPrime(4*n+1) and IsPrime(4*n+3)]; // Vincenzo Librandi, Feb 01 2015

Crossrefs

Cf. A005098, A005099, A095278.

Sequence in context: A296309 A182278 A032818 * A294914 A088405 A100591

Adjacent sequences: A123983 A123984 A123985 * A123987 A123988 A123989

Keyword

nonn

Author

Artur Jasinski, Oct 30 2006

Extensions

Extended by Ray Chandler, Nov 05 2006

Status

approved