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%I #9 Jan 28 2021 03:35:28
%S 6,9,54,4,264,308,7854,374,1564,11339,362848,127541072,1307295988,
%T 2614591976,42742894912,1132686715168,4608863185856,71437379380768,
%U 162734350229389504,46216555465146619136,427503138052606227008,270181983249247135469056,64347502466822129824768
%N Denominators of a sequence of fractions converging to A340820, the asymptotic density of numbers whose excess of prime divisors (A046660) is even (A162644).
%C See A340818 for details.
%H Amiram Eldar, <a href="/A340819/b340819.txt">Table of n, a(n) for n = 1..462</a>
%t d[p_] := 1/(p*(p + 1)); delta[n_] := delta[n] = d[Prime[n]]; f[0] = 1; f[n_] := f[n] = f[n - 1] * (1 - delta[n]) + (1 - f[n - 1]) * delta[n]; Denominator @ Array[f, 30]
%Y Cf. A046660, A162644, A340818 (numerators), A340820.
%K nonn,frac
%O 1,1
%A _Amiram Eldar_, Jan 22 2021