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 | 0 |
| 3 | -1 |
| 4 | -1 |
| 5 | -1 |
| 6 | 0 |
| 7 | 1 |
| 8 | 2 |
| 9 | 3 |
| 10 | 4 |
| 11 | 5 |
| 12 | 5 |
| 13 | 5 |
| 14 | 4 |
| 15 | 3 |
| 16 | 1 |
| 17 | -1 |
| 18 | -4 |
| 19 | -7 |
| 20 | -11 |
| 21 | -15 |
| 22 | -20 |
| 23 | -25 |
| 24 | -30 |
| 25 | -35 |
| 26 | -40 |
| 27 | -45 |
| 28 | -49 |
| 29 | -53 |
| 30 | -56 |
| 31 | -59 |
| 32 | -60 |
| 33 | -61 |
| 34 | -60 |
| 35 | -59 |
| 36 | -55 |
| 37 | -51 |
| 38 | -44 |
| 39 | -37 |
| 40 | -26 |
| 41 | -15 |
| 42 | 0 |
| 43 | 15 |
| 44 | 35 |
| 45 | 55 |
| 46 | 80 |
| 47 | 105 |
| 48 | 135 |
| 49 | 165 |
| 50 | 200 |
| 51 | 235 |
| 52 | 275 |
| 53 | 315 |
| 54 | 360 |
| 55 | 405 |
| 56 | 454 |
| 57 | 503 |
| 58 | 556 |
| 59 | 609 |
| 60 | 665 |
| 61 | 721 |
| 62 | 780 |
| 63 | 839 |
| 64 | 899 |
| 65 | 959 |
| 66 | 1020 |
| 67 | 1081 |
| 68 | 1141 |
| 69 | 1201 |
| 70 | 1260 |