Number of words on {1,1,1,2,2,2,3,3,3,4,4,4,...,n,n,n} avoiding the pattern 12345.

A266738

Number of words on {1,1,1,2,2,2,3,3,3,4,4,4,...,n,n,n} avoiding the pattern 12345.

Terms

    a(0) =1a(1) =1a(2) =20a(3) =1680a(4) =369600a(5) =117392909a(6) =46121962742

External references