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 | 1 |
| 3 | 25 |
| 4 | -15 |
| 5 | 4 |
| 6 | -553 |
| 7 | 455 |
| 8 | -224 |
| 9 | 44 |
| 10 | 32220 |
| 11 | -32664 |
| 12 | 22500 |
| 13 | -8316 |
| 14 | 1276 |
| 15 | -4934996 |
| 16 | 5825600 |
| 17 | -5028452 |
| 18 | 2640220 |
| 19 | -771980 |
| 20 | 96976 |
| 21 | 1985306180 |
| 22 | -2636260484 |
| 23 | 2688531560 |
| 24 | -1791505144 |
| 25 | 751934040 |
| 26 | -181539072 |
| 27 | 19298224 |
| 28 | -2096543510160 |
| 29 | 3060180107600 |
| 30 | -3555908800752 |
| 31 | 2830338574800 |
| 32 | -1521052125120 |
| 33 | 530958146400 |
| 34 | -109131456720 |
| 35 | 10054374704 |