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 | 7 |
| 2 | 147 |
| 3 | 3430 |
| 4 | 79233 |
| 5 | 1714314 |
| 6 | 32471124 |
| 7 | 450360372 |
| 8 | 0 |
| 9 | -313409171166 |
| 10 | -15459345780879 |
| 11 | -537166232508360 |
| 12 | -15185812043764453 |
| 13 | -348420909370148580 |
| 14 | -5588125164812112720 |
| 15 | 0 |
| 16 | 4783756561471246040577 |
| 17 | 254794190560328322173970 |
| 18 | 9445124186699596552669050 |