OFFSET
1,2
COMMENTS
For root of c: f(n) = (1+c)*f(n-1)/(f(n-1)^2+1).
a(9) has 102 digits. - Emeric Deutsch, Jul 29 2009
MAPLE
f[1] := 1: for n from 2 to 10 do f[n] := 3*f[n-1]/(1+f[n-1]^2) end do: seq(denom(f[n]), n = 1 .. 8); # Emeric Deutsch, Jul 29 2009
PROG
(PARI) f(n) = if (n==1, 1, 3*f(n-1)/(f(n-1)^2+1));
a(n) = denominator(f(n)); \\ Michel Marcus, Mar 04 2019
CROSSREFS
KEYWORD
nonn,frac
AUTHOR
Mark Dols, Jul 23 2009
EXTENSIONS
a(7) and a(8) from Emeric Deutsch, Jul 29 2009
Name edited by Michel Marcus, Mar 04 2019
STATUS
approved