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A064121 Nonprime numbers n such that the sum of aliquot divisors of n (A001065) and product of aliquot divisors of n (A048741) are both perfect squares. 2

%I #10 Jan 07 2020 09:07:05

%S 1,12,75,76,124,147,153,176,243,332,363,477,507,524,575,688,867,892,

%T 963,1075,1083,1421,1532,1573,1587,1611,1916,2032,2075,2224,2299,2401,

%U 2421,2523,2572,2883,2891,3100,3479,3776,3888,4107,4336,4527,4961,4975

%N Nonprime numbers n such that the sum of aliquot divisors of n (A001065) and product of aliquot divisors of n (A048741) are both perfect squares.

%H Amiram Eldar, <a href="/A064121/b064121.txt">Table of n, a(n) for n = 1..10000</a>

%t Select[ Range[5000], IntegerQ[ Sqrt[ Apply[ Plus, Delete[ Divisors[ # ], -1]]]] && IntegerQ[ Sqrt[ Apply[ Times, Delete[Divisors[ # ], -1]]]] && ! PrimeQ[ # ] & ]

%Y Variant of A064116. - _R. J. Mathar_, Oct 02 2008

%Y Cf. A064710.

%K easy,nonn

%O 1,2

%A _Robert G. Wilson v_, Oct 14 2001

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Last modified June 29 18:05 EDT 2024. Contains 373855 sequences. (Running on oeis4.)