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 | 4 |
| 2 | 14 |
| 3 | 69 |
| 4 | 396 |
| 5 | 2503 |
| 6 | 16905 |
| 7 | 119571 |
| 8 | 874771 |
| 9 | 6567181 |
| 10 | 50329363 |
| 11 | 392328944 |
| 12 | 3102523829 |
| 13 | 24839151315 |
| 14 | 201011560316 |
| 15 | 1642124006250 |
| 16 | 13527821578754 |
| 17 | 112279051170871 |
| 18 | 938188211057701 |
| 19 | 7887160187935198 |
| 20 | 66672792338916470 |
| 21 | 566452703137103796 |
| 22 | 4834838039006782636 |