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 | 9 |
| 3 | 96 |
| 4 | 1439 |
| 5 | 24758 |
| 6 | 476056 |
| 7 | 9841611 |
| 8 | 214997756 |
| 9 | 4900190330 |
| 10 | 115530636036 |
| 11 | 2800145556058 |
| 12 | 69446136484047 |
| 13 | 1756114394736162 |
| 14 | 45152546920446518 |
| 15 | 1177790435393100588 |
| 16 | 31111743336031473800 |
| 17 | 831007304851753985293 |
| 18 | 22416683345590695488558 |
| 19 | 610057933331757664054671 |