Number of permutations of 3 indistinguishable copies of 1..n with exactly 2 adjacent element pairs in decreasing order.
A151632
Number of permutations of 3 indistinguishable copies of 1..n with exactly 2 adjacent element pairs in decreasing order.
Terms
- a(0) =0a(1) =9a(2) =405a(3) =6750a(4) =83736a(5) =922347a(6) =9639783a(7) =98361900a(8) =992660346a(9) =9967494609a(10) =99857394225a(11) =999379243674
External references
- oeis: A151632