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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 29 |
| 4 | 215 |
| 5 | 2299 |
| 6 | 24610 |
| 7 | 290203 |
| 8 | 3664639 |
| 9 | 49665695 |
| 10 | 719356045 |
| 11 | 11100719773 |
| 12 | 181925519591 |
| 13 | 3157018912485 |
| 14 | 57848571473665 |
| 15 | 1116400995778789 |
| 16 | 22637359008083824 |
| 17 | 481232567245746693 |
| 18 | 10703530470036896333 |
| 19 | 248615220921060645505 |
| 20 | 6020095122314424497575 |