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A103931 Denominators of squares of harmonic numbers A001008/A002805. 1
1, 4, 36, 144, 3600, 400, 19600, 78400, 6350400, 6350400, 768398400, 768398400, 129859329600, 129859329600, 129859329600, 519437318400, 150117385017600, 16679709446400, 6021375110150400, 240855004406016, 26761667156224 (list; graph; refs; listen; history; internal format)
OFFSET

1,2

COMMENTS

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

FORMULA

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

CROSSREFS

Sequence in context: A204504 A083223 A102263 * A068589 A120077 A007407

Adjacent sequences:  A103928 A103929 A103930 * A103932 A103933 A103934

KEYWORD

nonn,easy,frac

AUTHOR

Wolfdieter Lang (wolfdieter.lang_AT_physik_DOT_uni-karlsruhe_DOT_de), Mar 24 2005

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Last modified February 13 08:12 EST 2012. Contains 205451 sequences.