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 | 1 |
| 4 | 9 |
| 5 | 1126 |
| 6 | 53825 |
| 7 | 302989 |
| 8 | 2285199 |
| 9 | 133296721 |
| 10 | 9731109349 |
| 11 | 1737376806937 |
| 12 | 372236638394027 |
| 13 | 94229801087550639 |
| 14 | 27818002500902930641 |
| 15 | 591930814558449521261 |
| 16 | 9591188150350759241842 |
| 17 | 2816408483135723327055984 |
| 18 | 1394771058490469072473603553 |
| 19 | 385768133102988434073147277769 |