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 | 28 |
| 4 | 87 |
| 5 | 270 |
| 6 | 838 |
| 7 | 2601 |
| 8 | 8073 |
| 9 | 25057 |
| 10 | 77772 |
| 11 | 241389 |
| 12 | 749224 |
| 13 | 2325444 |
| 14 | 7217721 |
| 15 | 22402387 |
| 16 | 69532605 |
| 17 | 215815536 |
| 18 | 669848995 |
| 19 | 2079079590 |
| 20 | 6453054306 |
| 21 | 20029011913 |
| 22 | 62166115329 |
| 23 | 192951400293 |
| 24 | 598883212792 |
| 25 | 1858815753705 |
| 26 | 5769398661408 |
| 27 | 17907079197016 |