a(n) = number of n-lettered words in the alphabet {1, 2, 3} with as many occurrences of the substring (consecutive subword) [1, 1, 2] as of [1, 2, 1].
A211289
a(n) = number of n-lettered words in the alphabet {1, 2, 3} with as many occurrences of the substring (consecutive subword) [1, 1, 2] as of [1, 2, 1].
Terms
- a(0) =1a(1) =3a(2) =9a(3) =25a(4) =71a(5) =204a(6) =582a(7) =1664a(8) =4774a(9) =13705a(10) =39395a(11) =113437a(12) =327077a(13) =944320a(14) =2730140a(15) =7903408a(16) =22907996a(17) =66480105a(18) =193156593a(19) =561852041a(20) =1636108387a(21) =4769383420a(22) =13917292514a(23) =40651107056a(24) =118849691074a(25) =347788333857
External references
- oeis: A211289