A125216 Semiprimes s such that s-/+4 are primes.

9, 15, 33, 57, 93, 177, 237, 267, 393, 453, 573, 597, 687, 723, 933, 1167, 1227, 1293, 1527, 1563, 1623, 1983, 2157, 2217, 2463, 2913, 3327, 3453, 3543, 4353, 4647, 5007, 5277, 5403, 5847, 5853, 6033, 6117, 6207, 6267, 6333, 6393, 7023, 7233, 8013, 8097

Offset: 1

Author

Zak Seidov, Nov 24 2006

Keywords

• nonn

Programs

Mathematica

Reap[Do[p=Prime[i];If[PrimeQ[p+8]&&Total[Last/@FactorInteger[p+4]]==2,Sow[p+4]],{i,2*10^3}]][[2,1]]
Select[Range[8100],PrimeOmega[#]==2&&AllTrue[#+{4,-4},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Oct 29 2017 *)