Number of possible draws of 2n pairs of consecutive cards from a set of 4n + 1 cards, so that the card that initially occupies the central position is not selected.

A283678

Number of possible draws of 2n pairs of consecutive cards from a set of 4n + 1 cards, so that the card that initially occupies the central position is not selected.

Terms

    a(0) =1a(1) =2a(2) =54a(3) =4500a(4) =771750a(5) =225042300a(6) =99843767100

External references