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 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 76 |
| 7 | 232 |
| 8 | 764 |
| 9 | 2620 |
| 10 | 9496 |
| 11 | 35695 |
| 12 | 140140 |
| 13 | 568360 |
| 14 | 2389192 |
| 15 | 10338315 |
| 16 | 46118592 |
| 17 | 211120144 |
| 18 | 992316928 |
| 19 | 4773362476 |
| 20 | 23500234512 |
| 21 | 118125854560 |
| 22 | 606106812640 |
| 23 | 3168660576795 |
| 24 | 16872323635132 |
| 25 | 91369920670420 |
| 26 | 503022250919640 |
| 27 | 2811920834508705 |