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A078814
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Smallest prime factor of Googolplex - n which exceeds 16.
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1
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OFFSET
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1,1
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COMMENTS
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Seventh term is not known. Sequence continues ?, 625392489737, 19, 37, 5419, 107, 23, 60149, 1733, 89, 8543, 17, 5261, 229, 8656871, 4273, 14009, 29, 509, 43628661784403, 24539783, 19, 347, 12414692011, 523, 151, 421, 35816135619181, 17, 23, 184309, ?, 181, 288481, 163, 41, 743, 13337, 71, 53, 19, 59, 113, 37957721, ... where the unknown numbers exceed 25 * 10^12. - Dario Alpern, Jul 03 2003
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LINKS
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MATHEMATICA
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(* For any individual n *) k = 17; While[ !PrimeQ[k] || PowerMod[10, 10^100, k] - n != 0, k += 2]; k
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PROG
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(PARI) a(n) = forprime(p=17, oo, if(Mod(10, p)^lift(Mod(10, p-1)^100) == n, return(p))); \\ Jinyuan Wang, Apr 17 2020
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CROSSREFS
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KEYWORD
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nonn,hard,more,fini
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AUTHOR
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STATUS
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approved
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