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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 11 |
| 6 | 39 |
| 7 | 125 |
| 8 | 532 |
| 9 | 2301 |
| 10 | 11010 |
| 11 | 54681 |
| 12 | 284023 |
| 13 | 1509851 |
| 14 | 8194902 |
| 15 | 45080652 |
| 16 | 250641356 |
| 17 | 1404374247 |
| 18 | 7917209005 |
| 19 | 44848645457 |
| 20 | 255055220735 |
| 21 | 1455247360000 |
| 22 | 8326191235902 |
| 23 | 47752990403133 |