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 | 1 |
| 3 | -1 |
| 4 | 2 |
| 5 | 3 |
| 6 | -3 |
| 7 | -3 |
| 8 | 2 |
| 9 | 6 |
| 10 | 11 |
| 11 | -12 |
| 12 | -21 |
| 13 | 12 |
| 14 | 11 |
| 15 | -6 |
| 16 | 24 |
| 17 | 50 |
| 18 | -61 |
| 19 | -140 |
| 20 | 75 |
| 21 | 140 |
| 22 | -61 |
| 23 | -50 |
| 24 | 24 |
| 25 | 120 |
| 26 | 274 |
| 27 | -375 |
| 28 | -1011 |
| 29 | 540 |
| 30 | 1475 |
| 31 | -540 |
| 32 | -1011 |
| 33 | 375 |
| 34 | 274 |
| 35 | -120 |
| 36 | 720 |
| 37 | 1764 |
| 38 | -2696 |
| 39 | -8085 |
| 40 | 4479 |
| 41 | 15456 |
| 42 | -5005 |
| 43 | -15456 |
| 44 | 4479 |
| 45 | 8085 |
| 46 | -2696 |
| 47 | -1764 |
| 48 | 720 |
| 49 | 5040 |
| 50 | 13068 |
| 51 | -22148 |
| 52 | -71639 |
| 53 | 42140 |
| 54 | 169266 |
| 55 | -50932 |
| 56 | -221389 |
| 57 | 50932 |
| 58 | 169266 |
| 59 | -42140 |
| 60 | -71639 |
| 61 | 22148 |
| 62 | 13068 |
| 63 | -5040 |
| 64 | 40320 |
| 65 | 109584 |
| 66 | -204436 |
| 67 | -699804 |
| 68 | 442665 |
| 69 | 1969380 |
| 70 | -575310 |
| 71 | -3176172 |
| 72 | 593523 |
| 73 | 3176172 |
| 74 | -575310 |
| 75 | -1969380 |
| 76 | 442665 |
| 77 | 699804 |
| 78 | -204436 |
| 79 | -109584 |
| 80 | 40320 |
| 81 | 362880 |
| 82 | 1026576 |
| 83 | -2093220 |
| 84 | -7488928 |
| 85 | 5124105 |
| 86 | 24465321 |
| 87 | -7192395 |
| 88 | -46885278 |
| 89 | 7343325 |
| 90 | 57764619 |
| 91 | -7343325 |
| 92 | -46885278 |
| 93 | 7192395 |
| 94 | 24465321 |
| 95 | -5124105 |
| 96 | -7488928 |
| 97 | 2093220 |
| 98 | 1026576 |
| 99 | -362880 |