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 | 1 |
| 2 | 1 |
| 3 | 4 |
| 4 | 1 |
| 5 | 286 |
| 6 | 7582 |
| 7 | 202028 |
| 8 | 6473625 |
| 9 | 226029577 |
| 10 | 8338249868 |
| 11 | 391526193477 |
| 12 | 19990594900630 |
| 13 | 1159906506684446 |
| 14 | 74890158861242740 |
| 15 | 5119732406649036418 |
| 16 | 380146984328280974281 |
| 17 | 30198665638519565614034 |
| 18 | 2555354508318427693497565 |