Upper-Trimmed Subsequence

The upper-trimmed subsequence of $x=\{x_n\}$ is the sequence $\lambda(x)$ obtained by dropping the first occurrence of $n$ for each $n$. If $x$ is a Fractal Sequence, then $\lambda(x)=x$.

See also Lower-Trimmed Subsequence

References

Kimberling, C. ``Fractal Sequences and Interspersions.'' Ars Combin. 45, 157-168, 1997.