A036939 Smallest n-digit prime containing only digits 2 and 9, or 0 if no such prime exists.
2, 29, 229, 2999, 22229, 0, 2222929, 22229299, 222229229, 2222229299, 22222229299, 0, 2222222229229, 22222222222229, 222222222229229, 2222222222229299, 22222222222922299, 0, 2222222222222292929
Offset: 1
Links
- Jinyuan Wang, Table of n, a(n) for n = 1..500
Programs
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Mathematica
Join[{2},Table[Min[Select[FromDigits/@(Join[#,{9}]&/@Tuples[{2,9},n]), IntegerLength[#]==n+1&&PrimeQ[#]&]],{n,20}]]/.\[Infinity]->0 (* Harvey P. Dale, Nov 08 2011 *)
Comments