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 | 4 |
| 3 | 11 |
| 4 | 29 |
| 5 | 80 |
| 6 | 219 |
| 7 | 597 |
| 8 | 1632 |
| 9 | 4459 |
| 10 | 12181 |
| 11 | 33280 |
| 12 | 90923 |
| 13 | 248405 |
| 14 | 678656 |
| 15 | 1854123 |
| 16 | 5065557 |
| 17 | 13839360 |
| 18 | 37809835 |
| 19 | 103298389 |
| 20 | 282216448 |
| 21 | 771029675 |
| 22 | 2106492245 |
| 23 | 5755043840 |
| 24 | 15723072171 |
| 25 | 42956232021 |
| 26 | 117358608384 |
| 27 | 320629680811 |
| 28 | 875976578389 |
| 29 | 2393212518400 |
| 30 | 6538378193579 |