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 | -1 |
| 3 | 2 |
| 4 | 2 |
| 5 | -4 |
| 6 | 3 |
| 7 | -5 |
| 8 | 10 |
| 9 | -9 |
| 10 | 5 |
| 11 | 14 |
| 12 | -28 |
| 13 | 27 |
| 14 | -20 |
| 15 | 8 |
| 16 | -42 |
| 17 | 84 |
| 18 | -84 |
| 19 | 70 |
| 20 | -40 |
| 21 | 13 |
| 22 | 132 |
| 23 | -264 |
| 24 | 270 |
| 25 | -240 |
| 26 | 160 |
| 27 | -78 |
| 28 | 21 |
| 29 | -429 |
| 30 | 858 |
| 31 | -891 |
| 32 | 825 |
| 33 | -600 |
| 34 | 351 |
| 35 | -147 |
| 36 | 34 |
| 37 | 1430 |
| 38 | -2860 |
| 39 | 3003 |
| 40 | -2860 |
| 41 | 2200 |
| 42 | -1430 |
| 43 | 735 |
| 44 | -272 |
| 45 | 55 |
| 46 | -4862 |
| 47 | 9724 |
| 48 | -10296 |
| 49 | 10010 |
| 50 | -8008 |
| 51 | 5577 |
| 52 | -3234 |
| 53 | 1496 |
| 54 | -495 |
| 55 | 89 |
| 56 | 16796 |
| 57 | -33592 |
| 58 | 35802 |
| 59 | -35360 |
| 60 | 29120 |
| 61 | -21294 |
| 62 | 13377 |
| 63 | -7072 |
| 64 | 2970 |
| 65 | -890 |
| 66 | 144 |
| 67 | -58786 |
| 68 | 117572 |
| 69 | -125970 |
| 70 | 125970 |
| 71 | -106080 |
| 72 | 80444 |
| 73 | -53508 |
| 74 | 30940 |
| 75 | -15015 |
| 76 | 5785 |
| 77 | -1584 |
| 78 | 233 |