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Search: id:A108519
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| A108519 |
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a(n) is the smallest natural number m such that (10^n)! - m is prime. |
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+0
2
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OFFSET
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1,1
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COMMENT
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If a(n) is composite then a(n)>10^(2n)+2*10^n. Conjecture: All terms are noncomposite numbers.
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EXAMPLE
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a(3)=6701 because (10^3)!-6701 is prime and for 0<m<6701 1000!-m is
composite.
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MATHEMATICA
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a[n_] := (For[m = 1, ! PrimeQ[(10^n)! - m], m++ ]; m); Do[Print[a[n]], {n, 3}]
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CROSSREFS
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Cf. A108518.
Adjacent sequences: A108516 A108517 A108518 this_sequence A108520 A108521 A108522
Sequence in context: A100841 A003389 A027019 this_sequence A062210 A049080 A129754
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KEYWORD
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more,nonn,bref
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AUTHOR
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Farideh Firoozbakht (mymontain(AT)yahoo.com), Jul 10 2005
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