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#18 by Charles R Greathouse IV at Thu Sep 08 08:46:24 EDT 2022
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| PROG
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(MAGMAMagma) [n: n in [1..1000] | IsIntegral(Factorial(n)/&+[d: d in Divisors(n)])]
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Discussion
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| Thu Sep 08
| 08:46
| OEIS Server: https://oeis.org/edit/global/2944
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#17 by Harvey P. Dale at Wed Jul 20 18:45:37 EDT 2022
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#16 by Harvey P. Dale at Wed Jul 20 18:45:34 EDT 2022
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| MATHEMATICA
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Select[Range[80], IntegerQ[#!/DivisorSigma[1, #]]&] (* Harvey P. Dale, Jul 20 2022 *)
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| STATUS
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approved
editing
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#15 by Alois P. Heinz at Thu Jul 11 19:22:02 EDT 2019
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#14 by Sean A. Irvine at Thu Jul 11 19:20:43 EDT 2019
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#13 by Sean A. Irvine at Thu Jul 11 19:20:36 EDT 2019
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| NAME
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NmbersNumbers m such that m! / sigma(m) is an integer.
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| STATUS
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approved
editing
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Discussion
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| Thu Jul 11
| 19:20
| Sean A. Irvine: Typo.
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#12 by N. J. A. Sloane at Fri May 03 13:03:39 EDT 2019
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#11 by N. J. A. Sloane at Fri May 03 13:03:31 EDT 2019
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| NAME
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Nmbers m such that m! / sigma(m) is an integer h where k! = the factorial of k (A000142) and sigma(k) = the sum of divisors of k (A000203)..
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| COMMENTS
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Corresponding values of integers are h: 1, 20, 60, 630, 2688, 201600, 3326400, 17107200, ...
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| STATUS
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proposed
editing
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Discussion
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| Fri May 03
| 13:03
| N. J. A. Sloane: edited
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#10 by Michel Marcus at Sat Apr 27 04:10:29 EDT 2019
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#9 by Michel Marcus at Sat Apr 27 04:10:26 EDT 2019
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| NAME
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Nmbers m such that m! / sigma(m) is an integer h where k! = the factorial fof k (A0000142A000142) and sigma(k) = the sum of divisors of k (A000203).
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| COMMENTS
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a(n) = numbers fromEquals A163162 without number 3.
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| STATUS
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proposed
editing
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