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 | 0 |
| 1 | 1 |
| 2 | 0 |
| 3 | -2 |
| 4 | 2 |
| 5 | 0 |
| 6 | 9 |
| 7 | -4 |
| 8 | 3 |
| 9 | 0 |
| 10 | -64 |
| 11 | 18 |
| 12 | -6 |
| 13 | 4 |
| 14 | 0 |
| 15 | 620 |
| 16 | -128 |
| 17 | 27 |
| 18 | -8 |
| 19 | 5 |
| 20 | 0 |
| 21 | -7536 |
| 22 | 1240 |
| 23 | -192 |
| 24 | 36 |
| 25 | -10 |
| 26 | 6 |
| 27 | 0 |
| 28 | 109032 |
| 29 | -15072 |
| 30 | 1860 |
| 31 | -256 |
| 32 | 45 |
| 33 | -12 |
| 34 | 7 |
| 35 | 0 |
| 36 | -1809984 |
| 37 | 218064 |
| 38 | -22608 |
| 39 | 2480 |
| 40 | -320 |
| 41 | 54 |
| 42 | -14 |
| 43 | 8 |
| 44 | 0 |
| 45 | 33562944 |
| 46 | -3619968 |
| 47 | 327096 |
| 48 | -30144 |
| 49 | 3100 |
| 50 | -384 |
| 51 | 63 |
| 52 | -16 |