OFFSET
0,1
COMMENTS
The sequence of real values x(n) = (1 - 1/2!)^((1/2! - 1/3!)^(...^(1/n! - 1/(n+1)!))) converges to two different limits depending on whether n is even or odd. This integer sequence gives the decimal expansion of the lower limit, to which the odd-indexed terms of {x(n)} converge.
LINKS
Rafik Zeraoulia, Does this a_n = ... have a finite limit?, Math Stackexchange.
EXAMPLE
0.54877354704085687513069922740691455562600046738030...
MATHEMATICA
(* note that FullSimplify[1/Factorial[i]-1/Factorial[i+1]] == i/Gamma[2 + i]
which is i/Factorial[1 + i] for integer i *)
sequence = Table[Fold[#2^#1 &, Table[i/(i + 1)!, {i, n, 1, -1}]], {n, 1, 15}];
ListLinePlot[N /@ sequence, PlotRange -> {0, 1}]
N[sequence[[-1]]]
N[sequence[[-2]]]
PROG
(PARI) my(N=99, y=(N/(N+1)!)); forstep(n=N-1, 1, -1, y = ((n/(n+1)!)^y)); y \\ Michel Marcus, Jul 05 2020
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
R Zeraoulia, Jun 26 2020
STATUS
approved