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) |
|---|---|
| 2 | 1 |
| 3 | 3 |
| 4 | 7 |
| 5 | 24 |
| 6 | 117 |
| 7 | 663 |
| 8 | 4824 |
| 9 | 40367 |
| 10 | 381554 |
| 11 | 4001849 |
| 12 | 46043780 |
| 13 | 576018785 |
| 14 | 7783281188 |
| 15 | 112953364381 |
| 16 | 1752128923245 |
| 17 | 28930230194371 |
| 18 | 506596534953769 |