Number of permutations of 3 indistinguishable copies of 1..n with exactly 4 adjacent element pairs in decreasing order.
A151634
Number of permutations of 3 indistinguishable copies of 1..n with exactly 4 adjacent element pairs in decreasing order.
Terms
- a(0) =0a(1) =0a(2) =405a(3) =128124a(4) =12750255a(5) =789300477a(6) =38464072830
External references
- oeis: A151634