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 | 0 |
| 3 | 1 |
| 4 | 5 |
| 5 | 23 |
| 6 | 257 |
| 7 | 1048 |
| 8 | 27219 |
| 9 | 137537 |
| 10 | 2725441 |
| 11 | 22377824 |
| 12 | 1221555748 |
| 13 | 7846888669 |
| 14 | 406966068706 |
| 15 | 5178802915485 |
| 16 | 417065722270965 |
| 17 | 3785224363874273 |