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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 6 |
| 4 | 18 |
| 5 | 24 |
| 6 | 202 |
| 7 | 203 |
| 8 | 814 |
| 9 | 2067 |
| 10 | 2178 |
| 11 | 2207 |
| 12 | 20402 |
| 13 | 25116 |
| 14 | 64493 |
| 15 | 82566 |
| 16 | 207067 |
| 17 | 2040402 |
| 18 | 2187142 |
| 19 | 2233097 |
| 20 | 6887078 |
| 21 | 79585891 |
| 22 | 211313148 |
| 23 | 249281986 |
| 24 | 8161664181 |
| 25 | 22222222222 |
| 26 | 26331005924 |
| 27 | 81294635989 |
| 28 | 2008491060208 |
| 29 | 2048192235518 |
| 30 | 2228557243297 |
| 31 | 2471952825156 |