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 | 5 |
| 3 | 22 |
| 4 | 197 |
| 5 | 2076 |
| 6 | 29527 |
| 7 | 477394 |
| 8 | 9248745 |
| 9 | 204340600 |
| 10 | 5111234891 |
| 11 | 142148945214 |
| 12 | 4362830874877 |
| 13 | 146338813894612 |
| 14 | 5328688224075231 |
| 15 | 209295914833477546 |
| 16 | 8821420994034588113 |
| 17 | 397128156446044087536 |
| 18 | 19019218255697847951955 |
| 19 | 965527468715744517674998 |