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 | 1 |
| 2 | 5 |
| 3 | 8 |
| 4 | 86 |
| 5 | 12 |
| 6 | 2418 |
| 7 | -6015 |
| 8 | 97271 |
| 9 | -490693 |
| 10 | 4991069 |
| 11 | -33481184 |
| 12 | 294850612 |
| 13 | -2232642956 |
| 14 | 18815166552 |
| 15 | -150373925928 |
| 16 | 1255171140378 |
| 17 | -10300278908424 |
| 18 | 86135158514634 |
| 19 | -717384480699522 |
| 20 | 6029697856319760 |
| 21 | -50699911500290454 |
| 22 | 428507430151063548 |