Number of permutations of 5 indistinguishable copies of 1..n with exactly 2 adjacent element pairs in decreasing order.
A151647
Number of permutations of 5 indistinguishable copies of 1..n with exactly 2 adjacent element pairs in decreasing order.
Terms
- a(0) =0a(1) =100a(2) =5925a(3) =167475a(4) =3882250a(5) =84320250a(6) =1791011475a(7) =37753995925a(8) =793816473600
External references
- oeis: A151647