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A128600
a(n) = the denominator of the continued fraction [[n/1];[n/2],[n/3],..,[n/n]], where [x] is floor(x).
3
1, 1, 2, 5, 8, 27, 44, 137, 305, 905, 1466, 7411, 11986, 33597, 91007, 322205, 521306, 2292156, 3708875, 15639101, 40100349, 106348943, 172076807, 1071988711, 2129108426, 5564227811, 13812311521, 53326260495, 86283685147, 492560346093
OFFSET
1,3
MAPLE
A128600 := proc(n) local a, i ; a := 1 ; for i from n-1 to 1 by -1 do a := floor(n/i)+1/a ; od ; RETURN(denom(a)) ; end: for n from 1 to 40 do printf("%d, ", A128600(n)) ; od ; # R. J. Mathar, Jun 06 2007
MATHEMATICA
Table[Denominator[FromContinuedFraction[Table[Floor[n/i], {i, 1, n}]]], {n, 1, 30}] (* Stefan Steinerberger, Jun 02 2007 *)
CROSSREFS
Sequence in context: A192476 A093365 A209865 * A078993 A066846 A304043
KEYWORD
frac,nonn
AUTHOR
Leroy Quet, Mar 12 2007
EXTENSIONS
More terms from Stefan Steinerberger and R. J. Mathar, Jun 02 2007
STATUS
approved