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 | 5 |
| 2 | 17 |
| 3 | 59 |
| 4 | 203 |
| 5 | 690 |
| 6 | 2308 |
| 7 | 7621 |
| 8 | 24913 |
| 9 | 80794 |
| 10 | 260303 |
| 11 | 834057 |
| 12 | 2660049 |
| 13 | 8449715 |
| 14 | 26747224 |
| 15 | 84407894 |
| 16 | 265647824 |
| 17 | 834016199 |
| 18 | 2612728134 |
| 19 | 8168761695 |
| 20 | 25494031748 |
| 21 | 79434416090 |
| 22 | 247130166428 |
| 23 | 767788267178 |
| 24 | 2382328079245 |