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 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 22 |
| 6 | 90 |
| 7 | 393 |
| 8 | 1789 |
| 9 | 8378 |
| 10 | 40050 |
| 11 | 194492 |
| 12 | 956448 |
| 13 | 4752519 |
| 14 | 23822571 |
| 15 | 120315345 |
| 16 | 611644737 |
| 17 | 3127389106 |
| 18 | 16072642890 |
| 19 | 82981119252 |
| 20 | 430187414196 |
| 21 | 2238469102212 |
| 22 | 11687227631892 |
| 23 | 61208286479382 |
| 24 | 321465732705594 |