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) |
|---|---|
| 1 | 1 |
| 2 | 2 |
| 3 | -3 |
| 4 | 3 |
| 5 | -12 |
| 6 | 11 |
| 7 | 4 |
| 8 | -30 |
| 9 | 70 |
| 10 | -50 |
| 11 | 5 |
| 12 | -60 |
| 13 | 255 |
| 14 | -450 |
| 15 | 274 |
| 16 | 6 |
| 17 | -105 |
| 18 | 700 |
| 19 | -2205 |
| 20 | 3248 |
| 21 | -1764 |
| 22 | 7 |
| 23 | -168 |
| 24 | 1610 |
| 25 | -7840 |
| 26 | 20307 |
| 27 | -26264 |
| 28 | 13068 |
| 29 | 8 |
| 30 | -252 |
| 31 | 3276 |
| 32 | -22680 |
| 33 | 89796 |
| 34 | -201852 |
| 35 | 236248 |
| 36 | -109584 |
| 37 | 9 |
| 38 | -360 |
| 39 | 6090 |
| 40 | -56700 |
| 41 | 316365 |
| 42 | -1077300 |
| 43 | 2171040 |
| 44 | -2345400 |
| 45 | 1026576 |
| 46 | 10 |
| 47 | -495 |
| 48 | 10560 |
| 49 | -127050 |
| 50 | 946638 |
| 51 | -4510275 |
| 52 | 13667720 |
| 53 | -25228500 |
| 54 | 25507152 |
| 55 | -10628640 |