|
|
A119526
|
|
Odd denominators of n * n-th harmonic number = A027611[2^n].
|
|
0
|
|
|
1, 1, 3, 35, 45045, 4512611027925, 2052546673789621992207225, 104326219460917277964091790659689347988584942875383375, 65134729714436885436168002936626505274493455112928327538888490982573786624726691153873697518277375333357875
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,3
|
|
COMMENTS
|
|
|
LINKS
|
|
|
FORMULA
|
a(n) = Denominator[2^n*Sum[1/k,{k,1,2^n}]]. a(n) = A027611[2^n].
|
|
MATHEMATICA
|
Denominator[Table[2^n*Sum[1/k, {k, 1, 2^n}], {n, 0, 10}]]
With[{nn=300}, Select[Denominator[Times@@@Thread[{Range[nn], HarmonicNumber[Range[nn]]}]], OddQ]] (* Harvey P. Dale, Sep 12 2016 *)
|
|
CROSSREFS
|
|
|
KEYWORD
|
frac,nonn
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|