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 | -13 |
| 2 | 65 |
| 3 | -156 |
| 4 | 273 |
| 5 | -1014 |
| 6 | 3497 |
| 7 | -6539 |
| 8 | 12116 |
| 9 | -39819 |
| 10 | 99086 |
| 11 | -178009 |
| 12 | 395044 |
| 13 | -988651 |
| 14 | 2103335 |
| 15 | -4237363 |
| 16 | 8806967 |
| 17 | -19098131 |
| 18 | 40962220 |
| 19 | -80207062 |
| 20 | 158661230 |
| 21 | -337459980 |
| 22 | 681006807 |
| 23 | -1307462312 |
| 24 | 2595164702 |