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 | 3 |
| 2 | 24 |
| 3 | 100 |
| 4 | 471 |
| 5 | 2043 |
| 6 | 8422 |
| 7 | 34818 |
| 8 | 137649 |
| 9 | 543655 |
| 10 | 2096508 |
| 11 | 8031948 |
| 12 | 30355155 |
| 13 | 113929497 |
| 14 | 423562614 |
| 15 | 1565841650 |
| 16 | 5745557853 |
| 17 | 20989365057 |
| 18 | 76206968356 |
| 19 | 275721399480 |
| 20 | 992423144247 |
| 21 | 3562075121911 |
| 22 | 12728422443654 |
| 23 | 45379998032202 |
| 24 | 161158522838105 |
| 25 | 571293893581389 |