Two-sided semiprimes: deleting any number of digits at left or at right, but not both, leaves a semiprime.

A086698

Two-sided semiprimes: deleting any number of digits at left or at right, but not both, leaves a semiprime.

Terms

    a(0) =4a(1) =6a(2) =9a(3) =46a(4) =49a(5) =69a(6) =94a(7) =469a(8) =626a(9) =694a(10) =914a(11) =934a(12) =939a(13) =949a(14) =4694a(15) =4934a(16) =4939a(17) =9134a(18) =9346a(19) =9586a(20) =62386a(21) =62614a(22) =91346a(23) =959939a(24) =6998339a(25) =91439939

External references