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 [2, 1, 3].
A211299
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 [2, 1, 3].
Terms
- a(0) =1a(1) =3a(2) =9a(3) =25a(4) =71a(5) =202a(6) =576a(7) =1643a(8) =4694a(9) =13434a(10) =38512a(11) =110577a(12) =317977a(13) =915753a(14) =2641181a(15) =7628464a(16) =22063605a(17) =63899510a(18) =185302479a(19) =538032124a(20) =1564079757a(21) =4552119931a(22) =13263345605a(23) =38686346248a(24) =112955785122a(25) =330131225222a(26) =965769993745
External references
- oeis: A211299