4 X 4 analog of A094943.

Terms

a(0) =1a(1) =26a(2) =256a(3) =2472a(4) =25056a(5) =250016a(6) =2499456a(7) =25002112a(8) =249995776a(9) =2500000256a(10) =25000032256a(11) =249999869952