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 | 2 |
| 3 | 9 |
| 4 | 38 |
| 5 | 140 |
| 6 | 701 |
| 7 | 2534 |
| 8 | 13294 |
| 9 | 48369 |
| 10 | 258430 |
| 11 | 947694 |
| 12 | 5114572 |
| 13 | 18872399 |
| 14 | 102539204 |
| 15 | 380143356 |
| 16 | 2075658454 |
| 17 | 7723000261 |
| 18 | 42330184638 |
| 19 | 157951859953 |
| 20 | 868376395790 |
| 21 | 3247811317907 |
| 22 | 17899895038348 |
| 23 | 67075896452000 |
| 24 | 370442993383238 |
| 25 | 1390392820937920 |
| 26 | 7692166179956366 |
| 27 | 28910883325637649 |
| 28 | 160184255555687056 |