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 | 2 |
| 3 | 10 |
| 4 | 74 |
| 5 | 730 |
| 6 | 9002 |
| 7 | 133210 |
| 8 | 2299754 |
| 9 | 45375130 |
| 10 | 1007179562 |
| 11 | 24840104410 |
| 12 | 673895590634 |
| 13 | 19944372341530 |
| 14 | 639455369290922 |
| 15 | 22079273878443610 |
| 16 | 816812844197444714 |
| 17 | 32232133532123179930 |
| 18 | 1351401783010933015082 |