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 | 5 |
| 3 | 22 |
| 4 | 105 |
| 5 | 518 |
| 6 | 2555 |
| 7 | 12565 |
| 8 | 61748 |
| 9 | 303470 |
| 10 | 1491567 |
| 11 | 7331205 |
| 12 | 36033501 |
| 13 | 177107406 |
| 14 | 870496256 |
| 15 | 4278555247 |
| 16 | 21029425081 |
| 17 | 103361226864 |
| 18 | 508028305120 |
| 19 | 2496997824041 |
| 20 | 12272934541014 |
| 21 | 60322408298439 |
| 22 | 296489232532277 |
| 23 | 1457267166329605 |
| 24 | 7162579146364783 |