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A327946 Nonunitary pseudoperfect numbers (A327945) that equal to the sum of a subset of their nonunitary divisors in a single way. 1

%I #5 Sep 30 2019 20:17:21

%S 24,36,80,112,200,312,352,392,408,416,456,552,588,684,696,744,888,984,

%T 1032,1088,1116,1128,1216,1272,1332,1416,1464,1472,1548,1608,1692,

%U 1704,1752,1856,1896,1908,1936,1984,1992,2124,2136,2196,2288,2328,2412,2424,2472

%N Nonunitary pseudoperfect numbers (A327945) that equal to the sum of a subset of their nonunitary divisors in a single way.

%C The nonunitary version of A064771.

%e The nonunitary divisors of 36 are {2, 3, 6, 12, 18), and {6, 12, 18} is the only subset that sums to 36.

%t nudiv[n_] := Module[{d = Divisors[n]}, Select[d, GCD[#, n/#] > 1 &]]; s = {}; Do[d = nudiv[n]; If[Total[d] < n, Continue[]]; c = SeriesCoefficient[Series[Product[1 + x^d[[i]], {i, Length[d]}], {x, 0, n}], n]; If[c == 1, AppendTo[s, n]], {n, 1, 700}]; s

%Y Cf. A064771, A064591, A064597, A295829, A327945.

%K nonn

%O 1,1

%A _Amiram Eldar_, Sep 30 2019

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Last modified May 3 08:06 EDT 2024. Contains 372206 sequences. (Running on oeis4.)