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 | 9 |
| 3 | 24 |
| 4 | 63 |
| 5 | 165 |
| 6 | 432 |
| 7 | 1131 |
| 8 | 2961 |
| 9 | 7752 |
| 10 | 20295 |
| 11 | 53133 |
| 12 | 139104 |
| 13 | 364179 |
| 14 | 953433 |
| 15 | 2496120 |
| 16 | 6534927 |
| 17 | 17108661 |
| 18 | 44791056 |
| 19 | 117264507 |
| 20 | 307002465 |
| 21 | 803742888 |
| 22 | 2104226199 |
| 23 | 5508935709 |
| 24 | 14422580928 |
| 25 | 37758807075 |
| 26 | 98853840297 |
| 27 | 258802713816 |