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%I #9 Aug 13 2021 06:35:42
%S 1,12,9720,212625000,350211660750000,165830100163770908250000,
%T 615072417899094252893747931729750000,
%U 186290124133142953867176980119009688414239626750000,309270713892913107006055533400699678031452505346679687500000
%N a(n) = denominator(Sum_{k=1..2*n} Bernoulli(1 + k) / ((1 + k) * k^(1 + k))).
%t r[n_] := Sum[BernoulliB[1 + k] / ((1 + k) * k^(1 + k)), {k, 1, 2*n}];
%t Table[r[n], {n, 0, 10}] // Denominator
%o (PARI) a(n) = denominator(sum(k=1, 2*n, bernfrac(1+k)/((1+k)*k^(1+k)))); \\ _Michel Marcus_, Aug 12 2021
%Y Cf. A346716 (numerator), A346718 (rational limit).
%K nonn,frac
%O 0,2
%A _Peter Luschny_, Aug 11 2021