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 | -6 |
| 2 | 350 |
| 3 | -56364 |
| 4 | 17824950 |
| 5 | -9334057876 |
| 6 | 7308698191340 |
| 7 | -7997684730384600 |
| 8 | 11655857682806336550 |
| 9 | -21824608434847162167300 |
| 10 | 51054382673481634917970500 |
| 11 | -145916894745749901373155951720 |
| 12 | 500306549034304293474784779805500 |
| 13 | -2026855002861172152744641068895033544 |