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 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 4 |
| 6 | 5 |
| 7 | 6 |
| 8 | 7 |
| 9 | 8 |
| 10 | 9 |
| 11 | 89 |
| 12 | 583 |
| 13 | 2562 |
| 14 | 8996 |
| 15 | 27013 |
| 16 | 72057 |
| 17 | 175016 |
| 18 | 393805 |
| 19 | 831384 |
| 20 | 14964895 |
| 21 | 171416216 |
| 22 | 1274511567 |
| 23 | 7351608748 |
| 24 | 35319494255 |
| 25 | 147208687584 |
| 26 | 546836589610 |
| 27 | 1845658907261 |
| 28 | 5742168041637 |
| 29 | 149870423643695 |
| 30 | 2452427105334001 |
| 31 | 25693720399771170 |