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 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | -3 |
| 5 | 10 |
| 6 | -23 |
| 7 | 48 |
| 8 | -92 |
| 9 | 171 |
| 10 | -321 |
| 11 | 626 |
| 12 | -1265 |
| 13 | 2576 |
| 14 | -5099 |
| 15 | 9478 |
| 16 | -15925 |
| 17 | 22617 |
| 18 | -21816 |
| 19 | -8506 |
| 20 | 121659 |
| 21 | -436121 |
| 22 | 1204710 |
| 23 | -2962759 |
| 24 | 6860591 |
| 25 | -15427559 |
| 26 | 34323613 |
| 27 | -76269455 |
| 28 | 169591278 |
| 29 | -376162414 |
| 30 | 827819644 |
| 31 | -1798045927 |
| 32 | 3839392935 |
| 33 | -8041078328 |