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A323392
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Positive integers that have a record number of divisors in Eisenstein integers.
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2
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1, 2, 3, 6, 12, 18, 21, 36, 42, 84, 126, 168, 252, 420, 504, 546, 1008, 1092, 1638, 2184, 3276, 5460, 6552, 7644, 9828, 10374, 13104, 15288, 16380, 20748, 31122, 38220, 41496, 62244, 103740, 124488, 145236, 186732, 207480, 248976, 290472, 311220, 435708, 622440, 726180, 871416
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OFFSET
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1,2
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COMMENTS
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Analog of A002182 and A279254, which list the positive integers that have a record number of divisors in rational integers and Gaussian integers respectively.
It seems that 21 is the largest odd term.
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LINKS
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EXAMPLE
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252 has 60 divisors up to association in Eisenstein integers, more than any previous positive integers, so 252 is a term.
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MAPLE
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vmax:= 0: recinds:= NULL:
for n from 1 to 100000 do
if v > vmax then vmax:= v; recinds:= recinds, n fi
od:
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MATHEMATICA
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f[p_, e_] := Switch[Mod[p, 3], 0, 2*e + 1, 1, (e + 1)^2, 2, e + 1]; eisNumDiv[1] = 1; eisNumDiv[n_] := Times @@ f @@@ FactorInteger[n]; seq = {}; emax = 0; Do[eis = eisNumDiv[n]; If[eis > emax, emax = eis; AppendTo[seq, n]], {n, 1, 10^6}]; seq (* Amiram Eldar, Mar 02 2020 *)
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PROG
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(PARI)
my(r=0, t); for(n=1, 10^6, t=A319442(n); if(t>r, r=t; print1(n, ", ")));
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CROSSREFS
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For the number of divisors of a(n) see A323393.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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