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 | -1 |
| 2 | 0 |
| 3 | -1 |
| 4 | 3 |
| 5 | -2 |
| 6 | 1 |
| 7 | -5 |
| 8 | 8 |
| 9 | -5 |
| 10 | 7 |
| 11 | -18 |
| 12 | 21 |
| 13 | -17 |
| 14 | 32 |
| 15 | -57 |
| 16 | 59 |
| 17 | -66 |
| 18 | 121 |
| 19 | -173 |
| 20 | 184 |
| 21 | -253 |
| 22 | 415 |
| 23 | -530 |
| 24 | 621 |
| 25 | -921 |
| 26 | 1360 |
| 27 | -1681 |
| 28 | 2163 |
| 29 | -3202 |
| 30 | 4401 |
| 31 | -5525 |
| 32 | 7528 |
| 33 | -10805 |
| 34 | 14327 |
| 35 | -18578 |
| 36 | 25861 |
| 37 | -35937 |
| 38 | 47232 |
| 39 | -63017 |
| 40 | 87659 |
| 41 | -119106 |
| 42 | 157481 |
| 43 | -213693 |
| 44 | 294424 |
| 45 | -395693 |
| 46 | 528655 |
| 47 | -721810 |
| 48 | 984541 |
| 49 | -1320041 |