Number of permutations of 3 indistinguishable copies of 1..n with exactly 3 adjacent element pairs in decreasing order.
A151633
Number of permutations of 3 indistinguishable copies of 1..n with exactly 3 adjacent element pairs in decreasing order.
Terms
- a(0) =0a(1) =1a(2) =760a(3) =49682a(4) =1722320a(5) =45699447a(6) =1063783164a(7) =23119658500a(8) =484099087156
External references
- oeis: A151633