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 | 0 |
| 2 | -2 |
| 3 | -3 |
| 4 | 4 |
| 5 | 1 |
| 6 | 1 |
| 7 | -9 |
| 8 | 13 |
| 9 | -9 |
| 10 | 20 |
| 11 | -38 |
| 12 | 76 |
| 13 | -75 |
| 14 | 65 |
| 15 | -323 |
| 16 | 378 |
| 17 | -197 |
| 18 | 805 |
| 19 | -1394 |
| 20 | 1635 |
| 21 | -2513 |
| 22 | 3175 |
| 23 | -5442 |
| 24 | 11135 |
| 25 | -12570 |
| 26 | 12526 |
| 27 | -33357 |
| 28 | 51563 |
| 29 | -46460 |
| 30 | 93551 |
| 31 | -155750 |
| 32 | 186650 |
| 33 | -313241 |
| 34 | 421641 |
| 35 | -620393 |
| 36 | 1131820 |
| 37 | -1321220 |
| 38 | 1663951 |
| 39 | -3559915 |
| 40 | 5011036 |
| 41 | -5207116 |