Number of sequences with n copies each of 1,2,3 avoiding the pattern 123.
A269121
Number of sequences with n copies each of 1,2,3 avoiding the pattern 123.
Terms
- a(0) =1a(1) =5a(2) =43a(3) =374a(4) =3199a(5) =26945a(6) =224296a(7) =1850672a(8) =15168751a(9) =123700631a(10) =1004849563a(11) =8137906034a(12) =65749071892a(13) =530209766156
External references
- oeis: A269121