Number of permutations of 3 indistinguishable copies of 1..n with exactly 9 adjacent element pairs in decreasing order.
A151639
Number of permutations of 3 indistinguishable copies of 1..n with exactly 9 adjacent element pairs in decreasing order.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =1a(4) =1722320a(5) =21475242671
External references
- oeis: A151639