2 up, 2 down, ..., 2 up, 2 down, 2 up permutations of length 4n+3.

A131454

2 up, 2 down, ..., 2 up, 2 down, 2 up permutations of length 4n+3.

Terms

    a(0) =1a(1) =71a(2) =45541a(3) =120686411a(4) =908138776681

External references