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 | 1 |
| 3 | 8 |
| 4 | 39 |
| 5 | 546 |
| 6 | 5482 |
| 7 | 109640 |
| 8 | 1709675 |
| 9 | 44451550 |
| 10 | 947113254 |
| 11 | 30307624128 |
| 12 | 821539580358 |
| 13 | 31218504053604 |
| 14 | 1028949571999572 |
| 15 | 45273781167981168 |
| 16 | 1758747856988046771 |
| 17 | 87937392849402338550 |
| 18 | 3935893923685215214030 |