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 | 5 |
| 2 | 12 |
| 3 | 73 |
| 4 | 418 |
| 5 | 3110 |
| 6 | 23920 |
| 7 | 207549 |
| 8 | 1885166 |
| 9 | 18417710 |
| 10 | 187881112 |
| 11 | 2018628090 |
| 12 | 22533601892 |
| 13 | 261966343388 |
| 14 | 3149344100224 |
| 15 | 39158513865053 |
| 16 | 501507474201750 |
| 17 | 6611648592425790 |
| 18 | 89492095211184360 |
| 19 | 1242626064512513070 |