Numbers k such that k, k + 1, k + 2, and k + 4 are all semiprimes.

Terms

a(0) =141a(1) =201a(2) =213a(3) =217a(4) =301a(5) =1137a(6) =1345a(7) =1401a(8) =1761a(9) =1837a(10) =1893a(11) =1941a(12) =1981a(13) =2101a(14) =3097a(15) =3865a(16) =3957a(17) =4413a(18) =4533a(19) =4881a(20) =5997a(21) =6157a(22) =6241a(23) =7113a(24) =7141a(25) =7165a(26) =7401a(27) =7977a(28) =8185a(29) =8257