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.
| n | a(n) |
|---|---|
| 0 | 1 |
| 1 | 1 |
| 2 | 2 |
| 3 | 9 |
| 4 | 40 |
| 5 | 192 |
| 6 | 963 |
| 7 | 5000 |
| 8 | 26649 |
| 9 | 144990 |
| 10 | 802023 |
| 11 | 4497150 |
| 12 | 25504380 |
| 13 | 146037955 |
| 14 | 843134220 |
| 15 | 4902661503 |
| 16 | 28686940053 |
| 17 | 168785282241 |
| 18 | 997968554037 |
| 19 | 5926617173205 |
| 20 | 35335723342962 |
| 21 | 211433954924955 |
| 22 | 1269252184538408 |
| 23 | 7642065274626855 |
| 24 | 46137678521488140 |