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 | -6 |
| 2 | 27 |
| 3 | -98 |
| 4 | 309 |
| 5 | -882 |
| 6 | 2330 |
| 7 | -5784 |
| 8 | 13644 |
| 9 | -30826 |
| 10 | 67107 |
| 11 | -141444 |
| 12 | 289746 |
| 13 | -578646 |
| 14 | 1129527 |
| 15 | -2159774 |
| 16 | 4052721 |
| 17 | -7474806 |
| 18 | 13569463 |
| 19 | -24274716 |
| 20 | 42838245 |
| 21 | -74644794 |
| 22 | 128533884 |
| 23 | -218881098 |
| 24 | 368859591 |
| 25 | -615513678 |
| 26 | 1017596115 |
| 27 | -1667593666 |
| 28 | 2710062756 |
| 29 | -4369417452 |