A090149 Primes of the form identical digits preceded by a 1.

11, 13, 17, 19, 199, 1777, 1999, 199999, 19999999, 1777777777, 17777777777777, 1333333333333333, 1111111111111111111, 11111111111111111111111, 199999999999999999999999999, 1999999999999999999999999999

Offset: 1

Author

Robert G. Wilson v, Nov 22 2003

Keywords

• nonn
• base

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..38

Programs

Mathematica

Select[FromDigits/@Flatten[Table[PadRight[{1},i,#]&/@{1,3,7,9},{i,2,40}],1],PrimeQ[#]&]

Extensions

Mathematica program modified by Harvey P. Dale, Jan 24 2019