

A109616


Numbers k such that (10's complement factorial of k) + 1 is prime.


1



2, 5, 10, 25, 36, 44, 65, 67, 138, 149, 176, 212, 279, 1293, 2367, 2463, 2707, 3130, 4150, 4635
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OFFSET

1,1


COMMENTS

Larger values not certified.
Some of the larger entries may only correspond to probable primes.


LINKS

Table of n, a(n) for n=1..20.


EXAMPLE

a(2)=5 because (105)*(104)*(103)*(102)*(101) + 1 = 15121 is prime.


MATHEMATICA

f[n_] := 10^Length[IntegerDigits[n]]  n; p = 1; Do[p *= f[n]; If[PrimeQ[p + 1], Print[n]], {n, 4635}] (* Ryan Propper, May 20 2006 *)


CROSSREFS

Cf. A110396.
Sequence in context: A324149 A054866 A242935 * A181785 A018262 A336542
Adjacent sequences: A109613 A109614 A109615 * A109617 A109618 A109619


KEYWORD

more,nonn,base


AUTHOR

Jason Earls, Aug 01 2005


EXTENSIONS

More terms from Ryan Propper, May 20 2006


STATUS

approved



