A048628 n-th 4k+1 prime times (n+1)st 4k+3 prime.

35, 143, 323, 667, 1147, 1763, 2491, 3599, 4891, 6319, 7663, 8383, 11227, 12091, 17399, 19519, 21823, 26123, 29503, 32231, 35263, 43739, 46367, 50851, 57311, 61063, 66203, 70531, 77059, 84823, 89711, 103459

Offset: 1

Author

Den Roussel (DenRoussel(AT)webtv.net)

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A002144, A002145, A022757.

Programs

Mathematica

Module[{nn=100,p1,p3,len},p1=Select[Prime[Range[nn]],Mod[#,4]==1&];p3= Rest[Select[Prime[Range[nn]],Mod[#,4]==3&]];len=Min[Length[p1], Length[ p3]];Times@@@Thread[{Take[p1,len],Take[p3,len]}]] (* Harvey P. Dale, Jan 09 2015 *)

Formula

a(n) = A002144(n) * A002145(n+1). - Sean A. Irvine, Jun 24 2021