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Denominator of Sum_{k=1..n} k^4 / Product_{k=1..n} k^4.
3

%I #10 May 09 2020 15:13:15

%S 1,16,648,55296,207360000,10749542400,23044331520000,

%T 220242357780480000,5780040437590917120000,3538800267912806400000000,

%U 115398507336502660300800000000,5264387585885382160794255360000000,1835850718442886445597615718400000000

%N Denominator of Sum_{k=1..n} k^4 / Product_{k=1..n} k^4.

%e The first few fractions are 1, 17/16, 49/648, 59/55296, 979/207360000, 91/10749542400, 167/23044331520000, ... = A181426/A334734.

%o (PARI) a(n) = denominator(sum(k=1, n, k^4)/prod(k=1, n, k^4)); \\ _Michel Marcus_, May 09 2020

%Y Cf. A166604, A181426 (numerators).

%K nonn,frac

%O 1,2

%A _Petros Hadjicostas_, May 09 2020