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%I #9 Aug 26 2022 05:25:33
%S 105,45045,237405,101846745,121486365,274680671265
%N (+2)-unitary sigma 3-multiple perfect number: numbers k such that (+2)usigma(k) = 3*k, where (+2)usigma(k) = A107759(k).
%e (+2)usigma(12) = (2+4)*(2+3) = 30.
%e Factorizations: 3*5*7, 3^2*5*7*11*13, 3*5*7^2*17*19, 3^2*5*7^2*11*13*17*19, 3^3*5*7*11*13*29*31, 3^3*5*7^2*11*13*17*19*29*31.
%t s[n_] := Times @@ (2 + Power @@@ FactorInteger[n]); s[1] = 1; Select[Range[2.5*10^5], s[#] == 3*# &] (* _Amiram Eldar_, Aug 26 2022 *)
%Y Cf. A052396, A107759.
%K nonn,more
%O 1,1
%A _Yasutoshi Kohmoto_
%E Offset corrected by _Amiram Eldar_, Aug 26 2022
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