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

[Max]

Paul D. Hanna wrote:

> Variations of this would include: 
> "a(n) = number of unique matrix products in (A+B+C+D)^n  where 
> commutator [A,B]=[A,D]=[B,D]=0 but D does not commute with A, B, or C." 

This one seems to be A052529

Max