In Figure 11 of the original Ichige publication (http://dspace.lib.niigata-u.ac.jp/dspace/bitstream/10191/6193/1/6_0011.pdf) the proposed filter lengths are different than the output of the function.
I myself have independently implemented Ichige's estimation formula and arrived at the same results as you.
Did you notice this deviation and did you try to contact the authors?
In Figure 11 of the original Ichige publication (http://dspace.lib.niigata-u.ac.jp/dspace/bitstream/10191/6193/1/6_0011.pdf) the proposed filter lengths are different than the output of the function.
I myself have independently implemented Ichige's estimation formula and arrived at the same results as you.
Did you notice this deviation and did you try to contact the authors?