Sphenic numbers that are sandwiched between products of exactly 4 distinct primes (or tetraprimes).

Terms

a(0) =18446a(1) =39766a(2) =74306a(3) =83434a(4) =94106a(5) =100346a(6) =107966a(7) =111154a(8) =111814a(9) =113366a(10) =140834a(11) =144754a(12) =145606a(13) =146014a(14) =147406a(15) =149854a(16) =154946a(17) =155702a(18) =156146a(19) =165346a(20) =171786a(21) =189034a(22) =190618a(23) =191806a(24) =197354a(25) =201686a(26) =203314a(27) =206194a(28) =211394a(29) =211946