A089023 Duplicate of A035610.
1, 4, 28, 232, 2092, 19864, 195352, 1970896, 20275660, 211823800, 2240795848
Offset: 0
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.