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 | 1 |
| 3 | 3 |
| 4 | 9 |
| 5 | 35 |
| 6 | 153 |
| 7 | 791 |
| 8 | 4597 |
| 9 | 29988 |
| 10 | 215804 |
| 11 | 1697291 |
| 12 | 14457059 |
| 13 | 132392971 |
| 14 | 1295346365 |
| 15 | 13468653637 |
| 16 | 148142236784 |
| 17 | 1716782858995 |
| 18 | 20889118889021 |