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 | 6 |
| 3 | 36 |
| 4 | 174 |
| 5 | -174 |
| 6 | -26076 |
| 7 | -596616 |
| 8 | -10334556 |
| 9 | -143486244 |
| 10 | -1157102136 |
| 11 | 19891298736 |
| 12 | 1443409042536 |
| 13 | 52915941558936 |
| 14 | 1542313273333104 |
| 15 | 37123741709607456 |
| 16 | 635436136388469744 |
| 17 | -1073509544497887216 |
| 18 | -801332217409556182176 |
| 19 | -51221481393025808800704 |