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 | 3 |
| 2 | 15 |
| 3 | 55 |
| 4 | 131 |
| 5 | 163 |
| 6 | -169 |
| 7 | -1521 |
| 8 | -4437 |
| 9 | -7429 |
| 10 | -2945 |
| 11 | 26471 |
| 12 | 101587 |
| 13 | 207699 |
| 14 | 201639 |
| 15 | -306497 |
| 16 | -1907461 |
| 17 | -4718165 |
| 18 | -6464305 |
| 19 | 547863 |
| 20 | 30463779 |
| 21 | 93816323 |
| 22 | 161591287 |
| 23 | 97035119 |
| 24 | -400669877 |
| 25 | -1676486565 |
| 26 | -3504149217 |
| 27 | -3693262649 |