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 | 0 |
| 1 | 1 |
| 2 | -9 |
| 3 | 126 |
| 4 | -2270 |
| 5 | 49995 |
| 6 | -1301139 |
| 7 | 39066076 |
| 8 | -1329148764 |
| 9 | 50536328085 |
| 10 | -2123542798685 |
| 11 | 97722882268506 |
| 12 | -4887863677728954 |
| 13 | 264025383760041631 |
| 14 | -15317578742680490535 |
| 15 | 949914821498248213560 |
| 16 | -62707584375936061905464 |
| 17 | 4390358319593012839913001 |