Number of permutations of 7 indistinguishable copies of 1..n with exactly 3 adjacent element pairs in decreasing order.

A151657

Number of permutations of 7 indistinguishable copies of 1..n with exactly 3 adjacent element pairs in decreasing order.

Terms

    a(0) =0a(1) =1225a(2) =818300a(3) =160310458a(4) =22727054364

External references