The lower-trimmed subsequence of is the sequence obtained by subtracting 1 from each and then removing all 0s. If is a Fractal Sequence, then is a Fractal Sequence. If is a Signature Sequence, then .
See also Signature Sequence, Upper-Trimmed Subsequence
Kimberling, C. ``Fractal Sequences and Interspersions.'' Ars Combin. 45, 157-168, 1997.