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A303996
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Numbers whose sum of divisors is the sixth power of one of their divisors.
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6
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1, 17490, 19410, 22578, 2823492, 162523452, 165982908, 216731788, 221416468, 221940628, 226768440, 230365560, 232815480, 234896520, 238942920, 240737160, 241362120, 242067720, 242454120, 242655720, 258182910, 264254670, 268298190, 272819070, 277297710, 286008510
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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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Divisors of 17490 are 1, 2, 3, 5, 6, 10, 11, 15, 22, 30, 33, 53, 55, 66, 106, 110, 159, 165, 265, 318, 330, 530, 583, 795, 1166, 1590, 1749, 2915, 3498, 5830, 8745, 17490 and their sum is 46656 = 6^6.
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MAPLE
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with(numtheory): P:=proc(q) local a, k, n;
for n from 1 to q do a:=sort([op(divisors(n))]);
for k from 1 to nops(a) do if sigma(n)=a[k]^6 then print(n); break; fi; od; od; end: P(10^9);
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PROG
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(PARI) isok(n) = (n==1) || (ispower(s=sigma(n), 6) && !(n % sqrtnint(s, 6))); \\ Michel Marcus, May 05 2018
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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