A204830 -id:A204830 - cp's OEIS frontend

A322377 Numbers n whose divisors can be partitioned into three disjoint sets whose sums are all sigma(n)/3 but no divisor of n has this property.

120, 180, 420, 504, 660, 672, 780, 1584, 1848, 1890, 2184, 2352, 2376, 2772, 2856, 3150, 3192, 4284, 4410, 4896, 5100, 5292, 5796, 6864, 6900, 6930, 7344, 7728, 8190, 8424, 9744, 10296, 10710, 11550, 11970, 12012, 12870, 13464, 13650, 13776, 14490, 14850, 15048, 15444

Offset: 1

David A. Corneth, Feb 18 2019

nonn

Primitive terms in A204830. If k is in A204830 then so is k*m.

Cf. A204830.

A355757 Smallest n-layered number.

Original entry on oeis.org

1, 6, 120, 27720, 147026880, 130429015516800, 1970992304700453905270400, 1897544233056092162003806758651798777216000

Offset: 1

Michel Marcus, Jul 20 2022

An integer k is said to be n-layered if the set of all positive divisors of k can be partitioned into n subsets with the same sum.

Farid Jokar, On k-layered numbers, arXiv:2207.09053 [math.NT], 2022.

Cf. k-layered numbers: A083207 (k=2), A204830 (k=3), A204831 (k=4).

cp's OEIS Frontend

A322377 Numbers n whose divisors can be partitioned into three disjoint sets whose sums are all sigma(n)/3 but no divisor of n has this property.

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