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A270780
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Let p_i = the i-th prime. a(i) is the smallest n>1 such that p_i divides n!-1.
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2
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3, 5, 9, 11, 5, 17, 4, 10, 15, 35, 39, 41, 45, 15, 18, 42, 48, 35, 17, 77, 41, 21, 43, 99, 96, 53, 22, 111, 125, 129, 120, 69, 25, 75, 155, 161, 83, 171, 177, 179, 189, 90, 195, 81, 105, 111, 82, 227, 101, 28, 239, 125, 255, 261, 267, 135, 236, 279, 141, 291
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OFFSET
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3,1
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COMMENTS
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Since p divides (p-2)!-1, the i-th term a(i) cannot be much larger than i log i.
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LINKS
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EXAMPLE
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For i=3, the third prime is 5, and 5 divides 3!-1.
The 7th prime is 17, and 17 divides 5!-1, so a(7)=5.
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MAPLE
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a:= proc(n) local k, p; p:=ithprime(n);
for k from 2 do if irem(k!, p)=1 then return k fi od
end:
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MATHEMATICA
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snpd[p_]:=Module[{n=2}, While[!Divisible[n!-1, p], n++]; n]; Table[snpd[p], {p, Prime[Range[3, 70]]}] (* Harvey P. Dale, Jun 06 2017 *)
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CROSSREFS
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KEYWORD
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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