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Second element s of (-1)sigma sociable triple (r,s,t): s=(-1)sigma(r), t=(-1)sigma(s), r=(-1)sigma(t), where if x=Product p(i)^r(i), then (-1)sigma(x)=Product(-1+(Sum p(i)^s(i), s(i)=1 to r(i))).
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%I #9 Jul 18 2021 01:55:18

%S 60,120,480,1464,7680,24504,490080

%N Second element s of (-1)sigma sociable triple (r,s,t): s=(-1)sigma(r), t=(-1)sigma(s), r=(-1)sigma(t), where if x=Product p(i)^r(i), then (-1)sigma(x)=Product(-1+(Sum p(i)^s(i), s(i)=1 to r(i))).

%C Definition unclear, see comments in A049057. - _Sean A. Irvine_, Jul 17 2021

%e Factorizations 2^2*3*5, 2^3*3*5, 2^5*3*5, 2^3*3*61, 2^9*3*5, 2^3*3*1021, 2^5*3*5*1021

%Y Cf. A049057, A049059, A049060.

%K nonn

%O 0,1

%A _Yasutoshi Kohmoto_