A105215 Minimum numerator among the n! ratios equal to the continued fractions which have the permutations of (1,2,3,...,n) for terms.

1, 3, 9, 37, 183, 1089, 7507, 59261, 525432, 5185027, 56276118, 667218665, 8572665529, 118743064065, 1763010417987, 27944432899993, 470820846422697, 8404897200626691, 158440099278231667, 3145660094900520781

Offset

1,2

Comments

Calculated by Vladeta Jovovic and David W. Wilson.

Links

Alois P. Heinz, Table of n, a(n) for n = 1..170

Maple

r:= proc(l) local j; infinity; for j to nops(l) do l[j] +1/% od end: gl:= proc(n) local u, o, l, r; u:= 1; o:= n; l:=NULL; r:=NULL; do if u>o then break fi; l:= l, u; u:= u+1; if u>o then break fi; r:= u, r; u:= u+1; if u>o then break fi; l:= l, o; o:= o-1; if u>o then break fi; r:= o, r; o:= o-1 od; [l, r] end: a:= n-> numer (r (gl (n))): seq (a(n), n=1..25); # Alois P. Heinz, Nov 18 2009

Mathematica

(* Script not suitable for more than a few terms *)
a[n_] := FromContinuedFraction /@ Permutations[Range[n]] // Numerator // Min;
Array[a, 10] (* Jean-François Alcover, Nov 18 2020 *)

Crossrefs

Cf. A105151.

Sequence in context: A006229 A321734 A008986 * A158053 A009179 A030819

Adjacent sequences: A105212 A105213 A105214 * A105216 A105217 A105218

Keyword

nonn

Author

Leroy Quet, Apr 12 2005

Extensions

More terms from Alois P. Heinz, Nov 18 2009

Status

approved