Given an Infinitive Sequence with associated array , then is said to be a fractal sequence
If is a fractal sequence, then the associated array is an Interspersion. If is a fractal sequence, then the Upper-Trimmed Subsequence is given by , and the Lower-Trimmed Subsequence is another fractal sequence. The Signature of an Irrational Number is a fractal sequence.
See also Infinitive Sequence
References
Kimberling, C. ``Fractal Sequences and Interspersions.'' Ars Combin. 45, 157-168, 1997.