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

1,1

Links

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

Mathematica

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

Crossrefs

Sequence in context: A327348 A327349 A240899 * A337834 A089691 A036979

Adjacent sequences: A090146 A090147 A090148 * A090150 A090151 A090152

Keyword

nonn,base

Author

Robert G. Wilson v, Nov 22 2003

Extensions

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

Status

approved