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 | -2 |
| 2 | 2 |
| 3 | 0 |
| 4 | -1 |
| 5 | -2 |
| 6 | 4 |
| 7 | 4 |
| 8 | -10 |
| 9 | -12 |
| 10 | 30 |
| 11 | 36 |
| 12 | -93 |
| 13 | -114 |
| 14 | 300 |
| 15 | 372 |
| 16 | -994 |
| 17 | -1244 |
| 18 | 3364 |
| 19 | 4240 |
| 20 | -11578 |
| 21 | -14676 |
| 22 | 40400 |
| 23 | 51448 |
| 24 | -142592 |
| 25 | -182288 |
| 26 | 508166 |
| 27 | 651756 |
| 28 | -1826037 |
| 29 | -2348562 |
| 30 | 6608844 |
| 31 | 8520564 |
| 32 | -24069258 |
| 33 | -31097388 |
| 34 | 88145436 |
| 35 | 114096096 |
| 36 | -324391422 |
| 37 | -420590652 |
| 38 | 1199074584 |