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 | 18 |
| 2 | 189 |
| 3 | 1518 |
| 4 | 10224 |
| 5 | 60552 |
| 6 | 324657 |
| 7 | 1606050 |
| 8 | 7429455 |
| 9 | 32458628 |
| 10 | 134950419 |
| 11 | 537136776 |
| 12 | 2056614597 |
| 13 | 7604901990 |
| 14 | 27248140107 |
| 15 | 94861629852 |
| 16 | 321652565253 |
| 17 | 1064430256536 |
| 18 | 3443952349385 |
| 19 | 10911585508344 |
| 20 | 33900910277472 |
| 21 | 103410118026774 |
| 22 | 310042892332701 |
| 23 | 914572545220908 |