A144246 - OEIS

A144246

Prime numbers of the form 10^k +- 9.

19, 109, 991, 1009, 10009, 99991, 9999991, 1000000009, 1000000000000000009, 10000000000000000000009, 999999999999999999999999999999991, 999999999999999999999999999999999999999999991

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OFFSET

1,1

COMMENTS

This sequence illustrates the base-n representation of numbers having the form n^k +- (n - 1).

LINKS

Table of n, a(n) for n=1..12.

MATHEMATICA

Select[Sort[Flatten[Table[10^n+{9, -9}, {n, 50}]]], PrimeQ] (* Harvey P. Dale, Jul 22 2016 *)

CROSSREFS

Cf. A000040, A000668, A144231, A144232, A144233, A144234, A144236, A144242, A144245

Sequence in context: A280628 A191566 A118607 * A281170 A158715 A372010

Adjacent sequences: A144243 A144244 A144245 * A144247 A144248 A144249

KEYWORD

nonn

AUTHOR

Reikku Kulon, Sep 15 2008

STATUS

approved