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A309542
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Numbers k such that A001414(k^3+1) is divisible by k.
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2
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1, 2, 5, 7, 20, 24, 45, 54, 286, 1942, 30771000, 71149819, 106438598, 668274063
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OFFSET
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1,2
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COMMENTS
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LINKS
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EXAMPLE
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5 is a member because the prime factorization of 5^3+1=126 is 2*3^2*7 and 2+3+3+7=15 is divisible by 5.
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MAPLE
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filter:= proc(n) local F, t;
F:= ifactors(n^3+1)[2];
add(t[1]*t[2], t=F) mod n = 0
end proc:
select(f, [$1..10000]);
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MATHEMATICA
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sopfr[n_] := Total[Times @@@ FactorInteger[n]];
okQ[n_] := Divisible[sopfr[n^3+1], n];
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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