a(n) is the smallest n-digit prime which remains prime whenever a 9 is inserted, appended or prepended, or 0 if no such prime exists.

A228150

a(n) is the smallest n-digit prime which remains prime whenever a 9 is inserted, appended or prepended, or 0 if no such prime exists.

Terms

    a(0) =7a(1) =19a(2) =199a(3) =1009a(4) =19417a(5) =160009a(6) =1086791a(7) =10301299a(8) =139993999a(9) =1391909989a(10) =10597399381a(11) =108979916999

External references