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 | 2 |
| 2 | 8 |
| 3 | 45 |
| 4 | 318 |
| 5 | 2671 |
| 6 | 25805 |
| 7 | 280609 |
| 8 | 3381993 |
| 9 | 44658052 |
| 10 | 640279918 |
| 11 | 9895457035 |
| 12 | 163871617543 |
| 13 | 2893296199441 |
| 14 | 54230087607409 |
| 15 | 1075060346670798 |
| 16 | 22467666780553040 |
| 17 | 493590689966427930 |
| 18 | 11369641989418301977 |