MathDB

If we write the sequence

\text{AAABABBB}

along the perimeter of a circle, then every word of the length

3

consisting of letters

A

and

B

(i.e.

\text{AAA}

\text{AAB}

\text{ABA}

\text{BAB}

\text{ABB}

\text{BBB}

\text{BBA}

\text{BAA}

) occurs exactly once on the perimeter. Decide whether it is possible to write a sequence of letters from a

k

-element alphabet along the perimeter of a circle in such a way that every word of the length

l

(i.e. an ordered

l

-tuple of letters) occurs exactly once on the perimeter.

Problem Statement