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The product of the two numbers in an amicable pair, A002025(n) * A002046(n).
4

%I #15 Dec 13 2020 05:15:43

%S 62480,1432640,7660880,27931280,39685376,116636864,179299575,

%T 318523136,4794813680,4483640576,4773473775,6100571295,7076217500,

%U 12475715175,17094480975,15069863936,21699524864,24011966300,30304399616

%N The product of the two numbers in an amicable pair, A002025(n) * A002046(n).

%C This sequence initially shares many terms with A180163 because small amicable pairs are sometimes consecutive terms in the sorted list of amicable numbers, A063990.

%C First differs from A180163 at a(9). - _Omar E. Pol_, Oct 25 2017

%H Amiram Eldar, <a href="/A180202/b180202.txt">Table of n, a(n) for n = 1..10000</a> (terms 1..1000 from T. D. Noe)

%F a(n) = A259180(2n-1) * A259180(2n). - _Omar E. Pol_, Oct 22 2017

%e a(9) = A002025(9) * A002046(9) = 63020 * 76084 = 4794813680.

%t s[n_] := DivisorSigma[1,n]-n; smallAmicableQ[n_] := Module[{b=s[n]}, n<b && s[b]==n]; a=Select[Range[10^6], smallAmicableQ]; Table[n*s[n],{n,a}]

%Y Cf. A002025, A002046, A180163, A259180.

%K nonn

%O 1,1

%A _T. D. Noe_, Aug 15 2010