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 | 3 |
| 2 | 6 |
| 3 | 16 |
| 4 | 63 |
| 5 | 351 |
| 6 | 2609 |
| 7 | 24636 |
| 8 | 284631 |
| 9 | 3909926 |
| 10 | 62459868 |
| 11 | 1140206571 |
| 12 | 23453446130 |
| 13 | 537365482536 |
| 14 | 13583603874930 |
| 15 | 375783149051267 |
| 16 | 11299149697288503 |
| 17 | 367080116280553305 |
| 18 | 12818485840320445236 |