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 | 9 |
| 2 | 49 |
| 3 | 257 |
| 4 | 1281 |
| 5 | 5913 |
| 6 | 23793 |
| 7 | 88273 |
| 8 | 306049 |
| 9 | 995241 |
| 10 | 3083569 |
| 11 | 9217057 |
| 12 | 26631041 |
| 13 | 74164665 |
| 14 | 198807793 |
| 15 | 513829617 |
| 16 | 1284656385 |
| 17 | 3117323593 |
| 18 | 7360510001 |
| 19 | 16939394369 |
| 20 | 38039783425 |
| 21 | 83427144281 |
| 22 | 178841051889 |