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 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 23 |
| 7 | 65 |
| 8 | 199 |
| 9 | 654 |
| 10 | 2296 |
| 11 | 8569 |
| 12 | 33825 |
| 13 | 140581 |
| 14 | 612933 |
| 15 | 2795182 |
| 16 | 13298464 |
| 17 | 65852873 |
| 18 | 338694479 |
| 19 | 1805812309 |
| 20 | 9963840219 |
| 21 | 56807228074 |
| 22 | 334192384460 |
| 23 | 2026044619017 |
| 24 | 12642938684817 |
| 25 | 81118550133657 |
| 26 | 534598577947465 |
| 27 | 3615474317688778 |
| 28 | 25070063421597484 |