Number of words on {1,1,2,2,3,3,...,n,n} avoiding the pattern 123.
A220097
Number of words on {1,1,2,2,3,3,...,n,n} avoiding the pattern 123.
Terms
- a(0) =1a(1) =1a(2) =6a(3) =43a(4) =352a(5) =3114a(6) =29004a(7) =280221a(8) =2782476a(9) =28221784a(10) =291138856a(11) =3045298326a(12) =32222872906a(13) =344293297768
External references
- oeis: A220097