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) |
|---|---|
| 1 | 1 |
| 2 | -2 |
| 3 | -5 |
| 4 | -10 |
| 5 | -42 |
| 6 | -112 |
| 7 | -429 |
| 8 | -1382 |
| 9 | -4837 |
| 10 | -16628 |
| 11 | -58786 |
| 12 | -207404 |
| 13 | -742900 |
| 14 | -2672724 |
| 15 | -9694425 |
| 16 | -35351906 |
| 17 | -129644790 |
| 18 | -477618082 |
| 19 | -1767263190 |
| 20 | -6564052564 |
| 21 | -24466262730 |
| 22 | -91482328496 |
| 23 | -343059613650 |
| 24 | -1289903299544 |
| 25 | -4861946399688 |
| 26 | -18367350100552 |
| 27 | -69533550867509 |
| 28 | -263747941045736 |
| 29 | -1002242216651368 |