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

A266735

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

Terms

    a(0) =1a(1) =1a(2) =6a(3) =90a(4) =2520a(5) =102011a(6) =5176504a(7) =307027744a(8) =20472135280

External references