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 | 23 |
| 3 | 103 |
| 4 | 473 |
| 5 | 2261 |
| 6 | 11215 |
| 7 | 57863 |
| 8 | 309713 |
| 9 | 1715653 |
| 10 | 9831911 |
| 11 | 58058375 |
| 12 | 353546473 |
| 13 | 2210900693 |
| 14 | 14215319903 |
| 15 | 93610866151 |
| 16 | 632159025185 |
| 17 | 4362925851653 |
| 18 | 30809311250743 |
| 19 | 221958273142823 |
| 20 | 1632956199823481 |
| 21 | 12238229941781845 |
| 22 | 93509510960341103 |
| 23 | 726913018468699463 |