Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 3 adjacent element pairs in decreasing order.
A151584
Number of permutations of 2 indistinguishable copies of 1..n arranged in a circle with exactly 3 adjacent element pairs in decreasing order.
Terms
- a(0) =0a(1) =36a(2) =1088a(3) =14220a(4) =134928a(5) =1093316a(6) =8120064a(7) =57280284a(8) =391301840
External references
- oeis: A151584