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A057232
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Numbers n such that n | 10^n + 9^n + 8^n.
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1
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1, 3, 9, 27, 81, 99, 243, 249, 729, 2187, 2781, 6561, 8019, 8667, 19683, 36207, 59049, 110457, 131549, 161269, 177147, 531441, 649539, 990711, 1325787, 1594323, 1633689, 4782969
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OFFSET
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1,2
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COMMENTS
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All terms are odd, and none are divisible by 5, 7 or 13.
If p is a prime > 3 that divides 8^(3^k)+9^(3^k)+10^(3^k), then 3^k*p is in the sequence. (End)
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LINKS
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MAPLE
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select(t -> 8&^t + 9&^t + 10&^t mod t = 0, [seq(seq(10*i+j), j=[1, 3, 7, 9]), i=0..10^6)]); # Robert Israel, Jan 02 2019
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MATHEMATICA
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Select[ Range[ 10^6 ], Mod[ PowerMod[ 10, #, # ] + PowerMod[ 9, #, # ] + PowerMod[ 8, #, # ], # ] == 0 & ]
Select[Range[5*10^6], Divisible[Total[PowerMod[{10, 9, 8}, #, #]], #]&] (* Harvey P. Dale, Feb 04 2015 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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