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 | 13 |
| 3 | 25 |
| 4 | 181 |
| 5 | 481 |
| 6 | 2653 |
| 7 | 8425 |
| 8 | 40261 |
| 9 | 141361 |
| 10 | 624493 |
| 11 | 2320825 |
| 12 | 9814741 |
| 13 | 37664641 |
| 14 | 155441533 |
| 15 | 607417225 |
| 16 | 2472715621 |
| 17 | 9761722321 |
| 18 | 39434309773 |
| 19 | 156574977625 |
| 20 | 629786694901 |
| 21 | 2508686426401 |
| 22 | 10066126765213 |
| 23 | 40170363882025 |