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 | -5 |
| 3 | -22 |
| 4 | -91 |
| 5 | -364 |
| 6 | -1430 |
| 7 | -5564 |
| 8 | -21541 |
| 9 | -83200 |
| 10 | -321100 |
| 11 | -1239446 |
| 12 | -4787770 |
| 13 | -18514119 |
| 14 | -71683040 |
| 15 | -277913233 |
| 16 | -1078918139 |
| 17 | -4194134516 |
| 18 | -16324764560 |
| 19 | -63616690111 |
| 20 | -248187382924 |
| 21 | -969250588865 |
| 22 | -3788814577730 |
| 23 | -14823325196459 |
| 24 | -58040165033110 |
| 25 | -227415509487686 |