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A339497
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Numbers k such that (k*i)^(1/4) is an integer for some i in 1 <= i <= k.
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2
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1, 4, 8, 9, 16, 25, 27, 32, 36, 48, 49, 54, 64, 72, 81, 100, 108, 121, 125, 128, 144, 162, 169, 192, 196, 200, 216, 225, 243, 250, 256, 288, 289, 324, 343, 361, 375, 384, 392, 400, 405, 432, 441, 484, 486, 500, 512, 529, 567, 576, 625, 640, 648, 675, 676, 686, 729, 768
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OFFSET
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1,2
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LINKS
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EXAMPLE
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9 is in the sequence since (9*9)^(1/4) = 3 (an integer), with 1 <= 9 <= 9.
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MAPLE
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filter:= proc(n) local F, x, t;
F:= ifactors(n)[2];
x:= mul(t[1]^(-t[2] mod 4), t=F);
x <= n
end proc:
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MATHEMATICA
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Table[If[Sum[1 - Ceiling[(n*k)^(1/4)] + Floor[(n*k)^(1/4)], {k, n}] > 0, n, {}], {n, 500}] // Flatten
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CROSSREFS
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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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