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 | 2 |
| 3 | 5 |
| 4 | 17 |
| 5 | 84 |
| 6 | 504 |
| 7 | 3523 |
| 8 | 28183 |
| 9 | 253643 |
| 10 | 2536423 |
| 11 | 27900646 |
| 12 | 334807751 |
| 13 | 4352500756 |
| 14 | 60935010579 |
| 15 | 914025158672 |
| 16 | 14624402538737 |
| 17 | 248614843158529 |
| 18 | 4475067176853513 |
| 19 | 85026276360216746 |
| 20 | 1700525527204334919 |
| 21 | 35711036071291033288 |
| 22 | 785642793568402732327 |