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 | 17 |
| 2 | 80 |
| 3 | 303 |
| 4 | 1039 |
| 5 | 3364 |
| 6 | 10493 |
| 7 | 31885 |
| 8 | 95032 |
| 9 | 279051 |
| 10 | 809771 |
| 11 | 2327372 |
| 12 | 6636025 |
| 13 | 18794633 |
| 14 | 52925984 |
| 15 | 148303719 |
| 16 | 413768263 |
| 17 | 1150029940 |
| 18 | 3185625077 |
| 19 | 8797726981 |
| 20 | 24230897416 |
| 21 | 66574108227 |