Primes of the form XYYYYYYYX, where Y is a single digit.

Terms

a(0) =188888881a(1) =199999991a(2) =322222223a(3) =355555553a(4) =722222227a(5) =17333333317a(6) =19555555519a(7) =21444444421a(8) =27888888827a(9) =29111111129a(10) =31333333331a(11) =31555555531a(12) =31666666631a(13) =39444444439a(14) =41999999941a(15) =43222222243a(16) =43666666643a(17) =47999999947a(18) =49333333349a(19) =49555555549