Semiprimes k such that k+1, k+2, 2*k+1 and 2*k+3 are also semiprimes.

Terms

a(0) =11733a(1) =15117a(2) =17245a(3) =28113a(4) =32365a(5) =34413a(6) =48745a(7) =78481a(8) =93453a(9) =101665a(10) =102957a(11) =105333a(12) =108753a(13) =134097a(14) =143101a(15) =157713a(16) =163801a(17) =170853a(18) =190621a(19) =208293a(20) =212545a(21) =233097a(22) =273417a(23) =274893a(24) =294301a(25) =300385a(26) =323281a(27) =346497a(28) =354565a(29) =363777