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 | 2 |
| 2 | 0 |
| 3 | 10 |
| 4 | -10 |
| 5 | 38 |
| 6 | -76 |
| 7 | 310 |
| 8 | -960 |
| 9 | 3190 |
| 10 | -10672 |
| 11 | 37262 |
| 12 | -130170 |
| 13 | 459690 |
| 14 | -1639940 |
| 15 | 5901498 |
| 16 | -21376154 |
| 17 | 77900710 |
| 18 | -285457200 |
| 19 | 1051118590 |
| 20 | -3887169486 |
| 21 | 14431323506 |
| 22 | -53766825940 |
| 23 | 200964040290 |
| 24 | -753348868380 |
| 25 | 2831669141514 |
| 26 | -10670007388128 |