Number of permutations of the multiset {1,1,1,2,2,2,3,3,3,...,n,n,n} with no two consecutive terms equal.

A193638

Number of permutations of the multiset {1,1,1,2,2,2,3,3,3,...,n,n,n} with no two consecutive terms equal.

Terms

    a(0) =1a(1) =0a(2) =2a(3) =174a(4) =41304a(5) =19606320a(6) =16438575600

External references