OFFSET
1,3
COMMENTS
Also u(n) = n*x(n-1)-1, where x(n) is defined in A220447.
LINKS
EXAMPLE
The sequence u(n) begins 1, 1, -10, -1, 19, -73/19, 662/73, -2795/331, 281/43, -4511/281, 21746/4511, ...
MAPLE
MATHEMATICA
x[n_] := x[n] = If[n == 1, 1, (x[n-1] + n)/(1 - n*x[n-1])];
u[n_] := If[n == 1, 1, n*x[n-1] - 1];
a[n_] := Numerator[u[n]];
Table[a[n], {n, 1, 29}] (* Jean-François Alcover, Aug 09 2023 *)
CROSSREFS
KEYWORD
sign,frac
AUTHOR
N. J. A. Sloane, Dec 22 2012
STATUS
approved