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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | 7 |
| 4 | 38 |
| 5 | 303 |
| 6 | 3424 |
| 7 | 53365 |
| 8 | 1121412 |
| 9 | 31197241 |
| 10 | 1131759944 |
| 11 | 52851880791 |
| 12 | 3141661092280 |
| 13 | 235381934211847 |
| 14 | 22034726000877312 |
| 15 | 2557207299577993717 |
| 16 | 365328083228276428304 |
| 17 | 63837414801921587915025 |
| 18 | 13564359864218330055841312 |
| 19 | 3485934653871954826576733959 |