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Denominators of squares of harmonic numbers A001008/A002805.
2

%I #5 Oct 16 2022 11:42:42

%S 1,4,36,144,3600,400,19600,78400,6350400,6350400,768398400,768398400,

%T 129859329600,129859329600,129859329600,519437318400,150117385017600,

%U 16679709446400,6021375110150400,240855004406016,26761667156224

%N Denominators of squares of harmonic numbers A001008/A002805.

%C The corresponding numerators are given in A103930. For the rational see the link there.

%F a(n)=denominator(H(n)^2), with the harmonic numbers H(n)=A001008(n)/A002805(n), n>=1.

%t Denominator[HarmonicNumber[Range[30]]^2] (* _Harvey P. Dale_, Oct 16 2022 *)

%K nonn,easy,frac

%O 1,2

%A _Wolfdieter Lang_, Mar 24 2005