Number of strings of length n over a 3-letter alphabet that do not begin with a nontrivial palindrome.
A252696
Number of strings of length n over a 3-letter alphabet that do not begin with a nontrivial palindrome.
Terms
- a(0) =0a(1) =3a(2) =6a(3) =12a(4) =30a(5) =78a(6) =222a(7) =636a(8) =1878a(9) =5556a(10) =16590a(11) =49548a(12) =148422a(13) =444630a(14) =1333254a(15) =3997884a(16) =11991774a(17) =35969766a(18) =107903742a(19) =323694636a(20) =971067318a(21) =2913152406a(22) =8739407670a(23) =26218074588a(24) =78654075342a(25) =235961781396a(26) =707884899558
External references
- oeis: A252696