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 | 24 |
| 3 | 122 |
| 4 | 640 |
| 5 | 3422 |
| 6 | 18536 |
| 7 | 101362 |
| 8 | 558336 |
| 9 | 3093302 |
| 10 | 17218168 |
| 11 | 96214890 |
| 12 | 539415552 |
| 13 | 3032659086 |
| 14 | 17091411912 |
| 15 | 96527966178 |
| 16 | 546184965120 |
| 17 | 3095613086822 |
| 18 | 17571039730136 |
| 19 | 99868193737306 |
| 20 | 568303494617472 |