The Minimal Algebraic Equation Satisfied by the Generating Function Enumerat\
ing 123-Avoiding Words of length, n
in the alphabet {1, ...,n}, where Each Letter Appears Exactly, 1, Times .
By Shalosh B. Ekhad
Theorem: Let a(n) be the number of words in the alphabet {1, ...,n} where ea\
ch letter occurs exactly, 1, times
and that avoid the pattern 123, in other words, there do not exist i1