Number of 9-ary words either empty or beginning with the first character of the alphabet, that can be built by inserting n doublets into the initially empty word.
A194729
Number of 9-ary words either empty or beginning with the first character of the alphabet, that can be built by inserting n doublets into the initially empty word.
Terms
- a(0) =1a(1) =1a(2) =17a(3) =353a(4) =8113a(5) =198401a(6) =5060433a(7) =133071009a(8) =3581326065a(9) =98156060225
External references
- oeis: A194729