Number of ternary 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.

A194723

Number of ternary 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) =5a(3) =29a(4) =181a(5) =1181a(6) =7941a(7) =54573a(8) =381333a(9) =2699837a(10) =19319845a(11) =139480397a(12) =1014536117a(13) =7426790749a(14) =54669443141a(15) =404388938349

External references