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 | 11 |
| 4 | 94 |
| 5 | 1076 |
| 6 | 15362 |
| 7 | 262171 |
| 8 | 5198778 |
| 9 | 117368024 |
| 10 | 2970653234 |
| 11 | 83287512901 |
| 12 | 2561682696970 |
| 13 | 85748218327188 |
| 14 | 3102969248315842 |
| 15 | 120702002794347559 |
| 16 | 5022388886172728830 |
| 17 | 222594275691025065632 |
| 18 | 10468834006648393288830 |
| 19 | 520740264878058965274931 |
| 20 | 27314609364943353454490482 |