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 | 1 |
| 2 | 3 |
| 3 | 13 |
| 4 | 66 |
| 5 | 366 |
| 6 | 2148 |
| 7 | 13115 |
| 8 | 82449 |
| 9 | 530095 |
| 10 | 3469401 |
| 11 | 23037642 |
| 12 | 154820262 |
| 13 | 1050999343 |
| 14 | 7196493255 |
| 15 | 49644745965 |
| 16 | 344704716018 |
| 17 | 2407157839593 |
| 18 | 16895247295947 |
| 19 | 119121868831235 |
| 20 | 843306880720218 |
| 21 | 5992060655349521 |
| 22 | 42718501097385207 |
| 23 | 305476181765843358 |