A215253 a(n) = decimal equivalent of A215254(n).
1, 2, 4, 9, 18, 37, 77, 150, 333, 601, 1202, 2405, 4941, 9622, 21325, 38489, 76978, 153957
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.