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 | 8 |
| 3 | 20 |
| 4 | 49 |
| 5 | 119 |
| 6 | 288 |
| 7 | 696 |
| 8 | 1681 |
| 9 | 4059 |
| 10 | 9800 |
| 11 | 23660 |
| 12 | 57121 |
| 13 | 137903 |
| 14 | 332928 |
| 15 | 803760 |
| 16 | 1940449 |
| 17 | 4684659 |
| 18 | 11309768 |
| 19 | 27304196 |
| 20 | 65918161 |
| 21 | 159140519 |
| 22 | 384199200 |
| 23 | 927538920 |
| 24 | 2239277041 |
| 25 | 5406093003 |
| 26 | 13051463048 |
| 27 | 31509019100 |
| 28 | 76069501249 |