|
%I #4 Dec 27 2017 01:30:45
%S 6,60,72,78,80,88,90,102,104,114,138,150,162,174,186,222,246,258,282,
%T 294,318,354,366,402,426,438,474,498,534,582,606,618,642,654,678,704,
%U 726,762,786,822,832,834,894,906,942,978,1002,1014,1038,1074,1086,1146
%N Bi-unitary pseudoperfect numbers that equal to the sum of a subset of their aliquot bi-unitary divisors in a single way.
%C The bi-unitary version of A064771.
%e 72 is in the sequence since its aliquot bi-unitary divisors are 1, 2, 4, 8, 9, 18, 36 and {1, 8, 9, 18, 36} is the only subset whose sum is 72.
%t f[n_] := Select[Divisors[n], Function[d, CoprimeQ[d, n/d]]]; bdiv[m_] := Select[Divisors[m], Last@Intersection[f@#, f[m/#]] == 1 &]; a={}; n=0;While[Length[a]<100,n++;d=Most[bdiv[n]];c = SeriesCoefficient[ Series[ Product[1+x^d[[i]],{i,Length[d]}],{x,0,n}],n ];If[c==1; AppendTo[a,n]]];a
%Y Cf. A064771, A292985.
%K nonn
%O 1,1
%A _Amiram Eldar_, Nov 28 2017
|
