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 | 21 |
| 2 | 441 |
| 3 | 1087 |
| 4 | 5132 |
| 5 | 18055 |
| 6 | 45520 |
| 7 | 140295 |
| 8 | 349415 |
| 9 | 877101 |
| 10 | 2164569 |
| 11 | 5025447 |
| 12 | 11757247 |
| 13 | 26570861 |
| 14 | 59370361 |
| 15 | 131185317 |
| 16 | 285043185 |
| 17 | 615447774 |
| 18 | 1313196034 |
| 19 | 2780365566 |
| 20 | 5844983027 |
| 21 | 12192162619 |
| 22 | 25292923072 |
| 23 | 52147005064 |
| 24 | 106956186914 |