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A109616
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Numbers n such that (10's complement factorial of n) + 1 is prime.
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1
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2, 5, 10, 25, 36, 44, 65, 67, 138, 149, 176, 212, 279, 1293, 2367, 2463, 2707, 3130, 4150, 4635
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Larger values not certified.
Some of the larger entries may only correspond to probable primes.
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EXAMPLE
| a(2)=5 because (10-5)*(10-4)*(10-3)*(10-2)*(10-1) + 1 = 15121 is prime.
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MATHEMATICA
| f[n_] := 10^Length[IntegerDigits[n]] - n; p = 1; Do[p *= f[n]; If[PrimeQ[p + 1], Print[n]], {n, 4635}] - Ryan Propper (rpropper(AT)stanford.edu), May 20 2006
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CROSSREFS
| Cf. A110396.
Sequence in context: A192471 A001431 A054866 * A181785 A018262 A018356
Adjacent sequences: A109613 A109614 A109615 * A109617 A109618 A109619
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KEYWORD
| more,nonn
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AUTHOR
| Jason Earls (zevi_35711(AT)yahoo.com), Aug 01 2005
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EXTENSIONS
| More terms from Ryan Propper (rpropper(AT)stanford.edu), May 20 2006
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