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 | 0 |
| 1 | 1 |
| 2 | 4 |
| 3 | 13 |
| 4 | 37 |
| 5 | 101 |
| 6 | 269 |
| 7 | 710 |
| 8 | 1865 |
| 9 | 4890 |
| 10 | 12810 |
| 11 | 33546 |
| 12 | 87834 |
| 13 | 229963 |
| 14 | 602062 |
| 15 | 1576231 |
| 16 | 4126639 |
| 17 | 10803695 |
| 18 | 28284455 |
| 19 | 74049680 |
| 20 | 193864595 |
| 21 | 507544116 |
| 22 | 1328767764 |
| 23 | 3478759188 |
| 24 | 9107509812 |
| 25 | 23843770261 |
| 26 | 62423800984 |
| 27 | 163427632705 |