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 | 0 |
| 2 | 3 |
| 3 | 5 |
| 4 | 16 |
| 5 | 43 |
| 6 | 113 |
| 7 | 316 |
| 8 | 839 |
| 9 | 2301 |
| 10 | 6204 |
| 11 | 16855 |
| 12 | 45665 |
| 13 | 123800 |
| 14 | 335659 |
| 15 | 909845 |
| 16 | 2466760 |
| 17 | 6686979 |
| 18 | 18128529 |
| 19 | 49145300 |
| 20 | 133231279 |
| 21 | 361184653 |
| 22 | 979156724 |
| 23 | 2654456239 |
| 24 | 7196122817 |
| 25 | 19508406192 |
| 26 | 52886508243 |
| 27 | 143373224101 |