Number of words of length 3*n that can be formed with a three-letter alphabet when the number of letters of each type is == 1 (mod 3).
A391469
Number of words of length 3*n that can be formed with a three-letter alphabet when the number of letters of each type is == 1 (mod 3).
Terms
- a(0) =0a(1) =6a(2) =90a(3) =2106a(4) =58806a(5) =1596510a(6) =43053282a(7) =1162202418a(8) =31380882462a(9) =847290203766
External references
- oeis: A391469