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a(n) = Sum_{r|n, s|n, t|n, r<s<t} r*s*t.
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%I #13 Mar 18 2023 17:40:06

%S 0,0,0,8,0,72,0,120,27,180,0,1400,0,336,360,1240,0,3285,0,3948,672,

%T 792,0,15960,125,1092,1080,8240,0,25992,0,11160,1584,1836,1680,57065,

%U 0,2280,2184,46620,0,56352,0,23592,18612,3312,0,150040,343,29955,3672

%N a(n) = Sum_{r|n, s|n, t|n, r<s<t} r*s*t.

%H Alois P. Heinz, <a href="/A067817/b067817.txt">Table of n, a(n) for n = 1..10000</a>

%F (1/3!)*(sigma[1](n)^3-3*sigma[1](n)*sigma[2](n)+2*sigma[3](n)).

%p a:= n-> coeff(expand(mul(1+d*x, d=numtheory[divisors](n))), x, 3):

%p seq(a(n), n=1..100); # _Alois P. Heinz_, Mar 18 2023

%o (PARI) a(n) = 1/6*(sigma(n, 1)^3 - 3*sigma(n, 1)*sigma(n, 2) + 2*sigma(n, 3)) \\ _Michel Marcus_, Jun 17 2013

%Y Cf. A067692, A068020, A000203, A001157, A001158.

%Y Column k=3 of A224381.

%K nonn

%O 1,4

%A _Vladeta Jovovic_, Feb 08 2002