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

%I #10 Aug 18 2015 00:20:10

%S 1,1,2,5,8,27,44,137,305,905,1466,7411,11986,33597,91007,322205,

%T 521306,2292156,3708875,15639101,40100349,106348943,172076807,

%U 1071988711,2129108426,5564227811,13812311521,53326260495,86283685147,492560346093

%N a(n) = the denominator of the continued fraction [[n/1];[n/2],[n/3],..,[n/n]], where [x] is floor(x).

%p 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

%t Table[Denominator[FromContinuedFraction[Table[Floor[n/i],{i, 1, n}]]],{n,1, 30}] (* _Stefan Steinerberger_, Jun 02 2007 *)

%Y Cf. A128599, A128601.

%K frac,nonn

%O 1,3

%A _Leroy Quet_, Mar 12 2007

%E More terms from _Stefan Steinerberger_ and _R. J. Mathar_, Jun 02 2007