A092761 Primes of the form prime(n)*prime(n+1) - 4.

2, 11, 31, 73, 139, 433, 1759, 2017, 5179, 6553, 8629, 10399, 14347, 16633, 20707, 39199, 53353, 131749, 159193, 186619, 216217, 250993, 471949, 509767, 608347, 736159, 777919, 938953, 1022113, 1065019, 1238749, 1327099, 1476217, 1640953

Offset: 1

Author

Giovanni Teofilatto, Apr 13 2004

Keywords

• nonn
• easy

Links

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

Programs

Mathematica

f[n_]:=Prime[n]*Prime[n+1]-4; lst={}; Do[If[PrimeQ[f[n]],AppendTo[lst,f[n]]],{n,6!}]; lst (* Vladimir Joseph Stephan Orlovsky, Feb 10 2010 *)
Select[Times@@@Partition[Prime[Range[250]],2,1]-4,PrimeQ] (* Harvey P. Dale, Oct 12 2015 *)

Extensions

Corrected and extended by Pab Ter (pabrlos(AT)yahoo.com), May 24 2004