a(n)=Number of Unique Matrix Products in (A+B+C)^n When [A,B]=0

[Joshua Zucker]

On 2/1/06, Max <relf at unn.ac.ru> wrote:

> It is in the OEIS under the name A001906

Max, or Paul: I think you should submit this comment!  (that this is
the number of distinct strings of n A's, B's, C's, if A's and B's
commute with each other but not with C's.

I also notice that A106431 is the exact same sequence as A001906: it
even says so in its title!  Certainly A106431 should be simply a
comment in A001906.

--Joshua Zucker