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 | 2 |
| 2 | 3 |
| 3 | 8 |
| 4 | 23 |
| 5 | 77 |
| 6 | 254 |
| 7 | 921 |
| 8 | 3249 |
| 9 | 12133 |
| 10 | 44937 |
| 11 | 172329 |
| 12 | 654895 |
| 13 | 2565963 |
| 14 | 9956885 |
| 15 | 39536964 |
| 16 | 156047622 |
| 17 | 626262315 |
| 18 | 2499486155 |
| 19 | 10129445626 |
| 20 | 40810378668 |
| 21 | 166475139700 |
| 22 | 676304156461 |
| 23 | 2775117950448 |
| 24 | 11342074888693 |
| 25 | 46785595997544 |
| 26 | 192244951610575 |
| 27 | 796245213910406 |