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, 3, 1].
A211291
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, 3, 1].
Terms
- a(0) =1a(1) =3a(2) =9a(3) =25a(4) =69a(5) =192a(6) =537a(7) =1508a(8) =4249a(9) =12009a(10) =34044a(11) =96795a(12) =275989a(13) =789040a(14) =2261594a(15) =6497986a(16) =18712521a(17) =54002913a(18) =156162531a(19) =452435327a(20) =1313117536a(21) =3817402150a(22) =11114803333a(23) =32408592752a(24) =94623871921a(25) =276620070867a(26) =809602760028
External references
- oeis: A211291