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) |
|---|---|
| 16 | 1 |
| 17 | -16 |
| 18 | 120 |
| 19 | -560 |
| 20 | 1804 |
| 21 | -4128 |
| 22 | 6312 |
| 23 | -3920 |
| 24 | -10530 |
| 25 | 42208 |
| 26 | -82752 |
| 27 | 99584 |
| 28 | -39460 |
| 29 | -141200 |
| 30 | 422568 |
| 31 | -673936 |
| 32 | 660941 |
| 33 | -144720 |
| 34 | -938840 |
| 35 | 2301568 |
| 36 | -3257188 |
| 37 | 2916592 |
| 38 | -628040 |
| 39 | -3492160 |
| 40 | 8217536 |
| 41 | -11341568 |
| 42 | 10408280 |
| 43 | -3885040 |
| 44 | -7668720 |
| 45 | 21033408 |