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

Author

Artur Jasinski, Oct 30 2006

Keywords

• nonn

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

Crossrefs

Cf. A005098, A005099, A095278.

Programs

Magma

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

Mathematica

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

Extensions

Extended by Ray Chandler, Nov 05 2006