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A275608
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Numbers that divide no nonzero terms of A003422.
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4
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3, 6, 8, 9, 12, 13, 15, 16, 18, 20, 21, 24, 25, 26, 27, 28, 29, 30, 32, 33, 35, 36, 39, 40, 42, 43, 44, 45, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 63, 64, 65, 66, 67, 68, 69, 70, 72, 75, 76, 78, 79, 80, 81, 83, 84, 85, 86, 87, 88, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99, 100
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OFFSET
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1,1
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COMMENTS
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Numbers k such that A013584(k) = 0.
If k is in the sequence, then so is every multiple of k.
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LINKS
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Robert Israel, Table of n, a(n) for n = 1..10000
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EXAMPLE
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3 is in the sequence because A003422(1)=1 and A003422(2)=2 are not divisible by 3, and A003422(k) == 1 (mod 3) for k >= 3.
4 is not in the sequence because A003422(3) = 4 is divisible by 4.
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MAPLE
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filter:= proc(n) local t, r, m;
r:= 1; t:= 1;
for m from 1 do
r:= r*m mod n;
if r = 0 then return true fi;
t:= t + r mod n;
if t = 0 then return false fi;
od;
end proc:
select(filter, [$2..100]);
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MATHEMATICA
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okQ[n_] := Module[{t, r, m}, r = 1; t = 1; For[m = 1, True, m++, r = Mod[r*m, n]; If[r == 0, Return[True]]; t = Mod[t + r, n]; If[t == 0, Return[False]]]];
Select[Range[2, 100], okQ] (* Jean-François Alcover, Apr 12 2019, after Robert Israel *)
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CROSSREFS
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Cf. A003422, A013584.
Complement of A049045.
Sequence in context: A167195 A032489 A153769 * A155723 A095277 A185717
Adjacent sequences: A275605 A275606 A275607 * A275609 A275610 A275611
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KEYWORD
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nonn,changed
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AUTHOR
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Robert Israel, Nov 14 2016
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STATUS
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approved
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