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) |
|---|---|
| 5 | 25 |
| 6 | 145 |
| 7 | 1009 |
| 8 | 8065 |
| 9 | 72577 |
| 10 | 725761 |
| 11 | 7983361 |
| 12 | 95800321 |
| 13 | 1245404161 |
| 14 | 17435658241 |
| 15 | 261534873601 |
| 16 | 4184557977601 |
| 17 | 71137485619201 |
| 18 | 1280474741145601 |
| 19 | 24329020081766401 |
| 20 | 486580401635328001 |
| 21 | 10218188434341888001 |