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, 3, 2].
A211300
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, 3, 2].
Terms
- a(0) =1a(1) =3a(2) =9a(3) =25a(4) =69a(5) =191a(6) =531a(7) =1483a(8) =4157a(9) =11691a(10) =32989a(11) =93391a(12) =265211a(13) =755375a(14) =2157529a(15) =6178887a(16) =17740209a(17) =51054977a(18) =147260321a(19) =425638453a(20) =1232663985a(21) =3576358773a(22) =10393851033a(23) =30255220019a(24) =88199249723a(25) =257469332747a(26) =752558722085
External references
- oeis: A211300