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 | 3 |
| 3 | 11 |
| 4 | 52 |
| 5 | 258 |
| 6 | 1344 |
| 7 | 7260 |
| 8 | 40290 |
| 9 | 228363 |
| 10 | 1316414 |
| 11 | 7694154 |
| 12 | 45491247 |
| 13 | 271594897 |
| 14 | 1635068538 |
| 15 | 9914851401 |
| 16 | 60503259435 |
| 17 | 371269891422 |
| 18 | 2289545742174 |
| 19 | 14181772631025 |
| 20 | 88194284530464 |
| 21 | 550444913949048 |
| 22 | 3446737067467311 |
| 23 | 21647081264988312 |