A128599 a(n) = the numerator of the continued fraction [[n/1];[n/2],[n/3],..,[n/n]] = the numerator of [[n/n];[n/(n-1)],[n/(n-2)],..,[n/1]], where [x] is floor(x).

1, 3, 7, 22, 43, 170, 321, 1127, 2816, 9221, 16403, 90121, 157741, 475003, 1377765, 5194616, 8925845, 41509031, 70873504, 314321071, 846062365, 2349224135, 3973214615, 25816158418, 53403343055, 145093944173, 373986049879

Offset

1,2

Links

Table of n, a(n) for n=1..27.

Maple

A128599 := 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(numer(a)) ; end: for n from 1 to 40 do printf("%d, ", A128599(n)) ; od ; # R. J. Mathar, Jun 02 2007

Mathematica

Table[Numerator[FromContinuedFraction[Table[Floor[n/i], {i, 1, n}]]], {n, 1, 30}] (* Stefan Steinerberger, Jun 02 2007 *)

Crossrefs

Cf. A128600, A128601.

Sequence in context: A174230 A158236 A174942 * A182174 A080882 A229807

Adjacent sequences: A128596 A128597 A128598 * A128600 A128601 A128602

Keyword

frac,nonn

Author

Leroy Quet, Mar 12 2007

Extensions

More terms from Stefan Steinerberger and R. J. Mathar, Jun 02 2007

Status

approved