A089346 Primes of the form identical odd digits followed by a 1.

11, 31, 71, 331, 991, 3331, 33331, 99991, 333331, 3333331, 9999991, 33333331, 555555555551, 5555555555551, 7777777777771, 333333333333333331, 1111111111111111111, 77777777777777777771, 11111111111111111111111

Offset

1,1

Links

Vincenzo Librandi, Table of n, a(n) for n = 1..44

Mathematica

Select[FromDigits/@Flatten[Table[Join[PadLeft[{n}, i, n], {1}], {i, 25}, {n, 1, 9, 2}], 1], PrimeQ] (* Harvey P. Dale, Jul 25 2011 *)

Crossrefs

Cf. A089345, A089347.

Sequence in context: A173803 A124704 A293659 * A296969 A038773 A054757

Adjacent sequences: A089343 A089344 A089345 * A089347 A089348 A089349

Keyword

base,nonn

Author

Amarnath Murthy, Nov 05 2003

Extensions

More terms from Ray Chandler, Nov 07 2003

Status

approved