A369590 a(n) = number of Yamanouchi words of length n that start with 3.
0, 0, 1, 2, 5, 14, 44, 139, 475, 1658, 6146, 23495, 93840, 385956, 1643862, 7193783, 32446635, 150049734, 712619582, 3462870079
Offset: 1
This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.