Number of strings of length n over a 9-letter alphabet that begin with a nontrivial palindrome.
A249642
Number of strings of length n over a 9-letter alphabet that begin with a nontrivial palindrome.
Terms
- a(0) =0a(1) =0a(2) =9a(3) =153a(4) =1449a(5) =13617a(6) =123129a(7) =1113273a(8) =10024569a(9) =90266553a(10) =812444409a(11) =7312407993a(12) =65812080249a(13) =592312391937
External references
- oeis: A249642