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 | 0 |
| 4 | -1 |
| 5 | 3 |
| 6 | -3 |
| 7 | 1 |
| 8 | 0 |
| 9 | -3 |
| 10 | 9 |
| 11 | -9 |
| 12 | 3 |
| 13 | 1 |
| 14 | -9 |
| 15 | 22 |
| 16 | -22 |
| 17 | 9 |
| 18 | 2 |
| 19 | -22 |
| 20 | 51 |
| 21 | -51 |
| 22 | 22 |
| 23 | 6 |
| 24 | -51 |
| 25 | 108 |
| 26 | -108 |
| 27 | 50 |
| 28 | 13 |
| 29 | -108 |
| 30 | 221 |
| 31 | -221 |
| 32 | 105 |
| 33 | 29 |
| 34 | -220 |
| 35 | 429 |
| 36 | -429 |
| 37 | 212 |
| 38 | 57 |
| 39 | -426 |
| 40 | 810 |
| 41 | -810 |
| 42 | 407 |
| 43 | 113 |
| 44 | -801 |
| 45 | 1479 |
| 46 | -1478 |
| 47 | 759 |
| 48 | 208 |
| 49 | -1457 |
| 50 | 2640 |
| 51 | -2637 |
| 52 | 1371 |
| 53 | 381 |
| 54 | -2589 |
| 55 | 4598 |
| 56 | -4590 |
| 57 | 2419 |
| 58 | 669 |