A295829 Unitary pseudoperfect numbers that equal to the sum of a subset of their aliquot unitary divisors in a single way.

6, 60, 78, 90, 102, 114, 138, 150, 174, 186, 222, 246, 258, 282, 294, 318, 354, 366, 402, 426, 438, 474, 498, 534, 582, 606, 618, 642, 654, 678, 726, 750, 762, 786, 822, 834, 894, 906, 942, 978, 1002, 1014, 1038, 1074, 1086, 1146, 1158, 1182, 1194, 1266, 1338

Offset

1,1

Comments

The unitary version of A064771.

It appears that most of the terms are divisible by 3. Terms that are not divisible by 3 are 3770, 5530, 7210, 7630, ... - Michel Marcus, Dec 15 2017

The least odd term is 442365. - Amiram Eldar, Jun 10 2020

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

150 is in the sequence since its aliquot unitary divisors are 1, 2, 3, 6, 25, 50, 75 and there is only one subset whose sum is 150: {25, 50, 75}.

Mathematica

ud[n_] := Block[{d = Divisors[n]}, Select[d, GCD[#, n/#] == 1 &]];
a = {}; n = 0; While[Length[a] < 100, n++; d = Most[ud[n]];
c = SeriesCoefficient[Series[Product[1 + x^d[[i]], {i, Length[d]}], {x, 0, n}], n]; If[c ==1, AppendTo[a, n]]]; a

Crossrefs

Cf. A064771, A293188.

Sequence in context: A295830 A335937 A136937 * A074452 A168618 A185288

Adjacent sequences: A295826 A295827 A295828 * A295830 A295831 A295832

Keyword

nonn

Author

Amiram Eldar, Nov 28 2017

Status

approved