a(n) = number of n-lettered words in the alphabet {1, 2, 3} with as many occurrences of the substring (consecutive subword) [1, 2, 1] as of [1, 3, 1].
A211297
a(n) = number of n-lettered words in the alphabet {1, 2, 3} with as many occurrences of the substring (consecutive subword) [1, 2, 1] as of [1, 3, 1].
Terms
- a(0) =1a(1) =3a(2) =9a(3) =25a(4) =69a(5) =195a(6) =555a(7) =1573a(8) =4457a(9) =12677a(10) =36165a(11) =103323a(12) =295639a(13) =847587a(14) =2434755a(15) =7006089a(16) =20193261a(17) =58296927a(18) =168567687a(19) =488155597a(20) =1415686337a(21) =4111268669a(22) =11955274925a(23) =34808988199a(24) =101471734355a(25) =296139036809a(26) =865204909777
External references
- oeis: A211297