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 | 3 |
| 3 | 5 |
| 4 | 21 |
| 5 | 82 |
| 6 | 249 |
| 7 | 688 |
| 8 | 1879 |
| 9 | 5690 |
| 10 | 17932 |
| 11 | 55271 |
| 12 | 164427 |
| 13 | 485348 |
| 14 | 1451110 |
| 15 | 4395114 |
| 16 | 13313135 |
| 17 | 40073992 |
| 18 | 120200822 |
| 19 | 360897368 |
| 20 | 1086543152 |
| 21 | 3274191643 |
| 22 | 9858847241 |
| 23 | 29657925485 |
| 24 | 89206237151 |
| 25 | 268435863317 |
| 26 | 808022052324 |
| 27 | 2432169981689 |
| 28 | 7319562671432 |