OFFSET
1,2
COMMENTS
The frequency depth of a word is the number of times one must take the multiset of multiplicities to reach the singleton (1), without rearranging it.
For example, the word (11213331) has frequency depth 7: (11213331) -> (21131) -> (1211) -> (112) -> (21) -> (11) -> (2) -> (1).
EXAMPLE
The shortest words of frequency depth 10 are of the form (112122112112122122112) and (112122122112112122112), up to substitution and reflection.
CROSSREFS
KEYWORD
nonn,hard,more
AUTHOR
Ludovic Schwob, Sep 21 2019
EXTENSIONS
Incorrect terms removed by Samuel B. Reid, Aug 25 2021
STATUS
approved