A089346 - OEIS

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

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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