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%I #8 Feb 04 2020 03:57:12
%S 0,1,1,1,1,6,1,7,1,8,1,8,1,10,9,11,1,12,1,10,11,14,1,36,1,16,13,12,1,
%T 42,1,31,15,20,13,14,1,22,17,50,1,54,1,16,15,26,1,60,1,28,21,18,1,66,
%U 17,64,23,32,1,60,1,34,17,55,19,78,1,22,27,74,1,78,1
%N The sum of the proper bi-unitary divisors of n.
%C First differs from A126168 at n = 16.
%H Amiram Eldar, <a href="/A331970/b331970.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = A188999(n) - n.
%e a(6) = 6 since A188999(6) - 6 = 12 - 6 = 6.
%t fun[p_, e_] := If[OddQ[e], (p^(e+1)-1)/(p-1), (p^(e+1)-1)/(p-1)-p^(e/2)]; bsigma[1] = 1; bsigma[n_] := bsigma[n] = Times @@ (fun @@@ FactorInteger[n]); bs[n_] := bsigma[n] - n; Array[bs, 100]
%Y Cf. A001065, A034460, A126164, A126168, A188999, A222266.
%K nonn
%O 1,6
%A _Amiram Eldar_, Feb 03 2020
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