Number of permutations of 2 indistinguishable copies of 1..n with exactly 8 adjacent element pairs in decreasing order.

A151630

Number of permutations of 2 indistinguishable copies of 1..n with exactly 8 adjacent element pairs in decreasing order.

Terms

    a(0) =0a(1) =0a(2) =0a(3) =0a(4) =1a(5) =37257a(6) =49258935a(7) =19323413187

External references