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 | 0 |
| 1 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 12 |
| 5 | 26 |
| 6 | 60 |
| 7 | 145 |
| 8 | 336 |
| 9 | 796 |
| 10 | 1880 |
| 11 | 4412 |
| 12 | 10400 |
| 13 | 24488 |
| 14 | 57648 |
| 15 | 135794 |
| 16 | 319744 |
| 17 | 752908 |
| 18 | 1773016 |
| 19 | 4175032 |
| 20 | 9831472 |
| 21 | 23151400 |
| 22 | 54516976 |
| 23 | 128377380 |
| 24 | 302304640 |
| 25 | 711870368 |
| 26 | 1676321856 |
| 27 | 3947423264 |
| 28 | 9295440640 |
| 29 | 21889019712 |
| 30 | 51544533376 |
| 31 | 121377706184 |