a(n) = number of n-lettered words in the alphabet {1, 2, 3} with as many occurrences of the substring (consecutive subword) [1, 2] as of [2, 3].
A211281
a(n) = number of n-lettered words in the alphabet {1, 2, 3} with as many occurrences of the substring (consecutive subword) [1, 2] as of [2, 3].
Terms
- a(0) =1a(1) =3a(2) =7a(3) =17a(4) =45a(5) =123a(6) =337a(7) =927a(8) =2575a(9) =7225a(10) =20427a(11) =58085a(12) =165967a(13) =476241a(14) =1371615a(15) =3962817a(16) =11480157a(17) =33335691a(18) =96998137a(19) =282751095a(20) =825549445a(21) =2413818011a(22) =7066833237a(23) =20713316043a(24) =60775993945a(25) =178497281223a(26) =524702227369
External references
- oeis: A211281