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A137848 Numbers k such that 10^k + 81 is prime. 1
2, 6, 8, 17, 22, 39, 89, 143, 167, 312, 334, 357, 414, 2254, 2694, 24094, 42081, 78632 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The next term, if one exists, is >100000. - Robert Price, Apr 25 2011

LINKS

Table of n, a(n) for n=1..18.

EXAMPLE

10^2+81=100+81=181 is prime

MATHEMATICA

Select[10^Range[25000] + 81, PrimeQ] (* Alonso del Arte, Dec 27 2010 *)

PROG

(PARI) is(n)=ispseudoprime(10^n+81) \\ Charles R Greathouse IV, Jun 13 2017

CROSSREFS

Sequence in context: A238549 A237502 A279726 * A182629 A183212 A053355

Adjacent sequences:  A137845 A137846 A137847 * A137849 A137850 A137851

KEYWORD

nonn

AUTHOR

Vladimir Joseph Stephan Orlovsky, May 06 2008

EXTENSIONS

Added three terms: 2254,2694,24094. Robert Price, Oct 09 2010

a(17)=42081 from Robert Price, Dec 27 2010

a(18)=78632 from Robert Price, Mar 03 2011

STATUS

approved

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Last modified September 26 05:09 EDT 2017. Contains 292502 sequences.