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 | 0 |
| 3 | -3 |
| 4 | 0 |
| 5 | 0 |
| 6 | 6 |
| 7 | -7 |
| 8 | 0 |
| 9 | -10 |
| 10 | 21 |
| 11 | -11 |
| 12 | 15 |
| 13 | -42 |
| 14 | 61 |
| 15 | -36 |
| 16 | 70 |
| 17 | -150 |
| 18 | 150 |
| 19 | -124 |
| 20 | 278 |
| 21 | -441 |
| 22 | 375 |
| 23 | -468 |
| 24 | 909 |
| 25 | -1131 |
| 26 | 1018 |
| 27 | -1581 |
| 28 | 2602 |
| 29 | -2810 |
| 30 | 2947 |
| 31 | -4819 |
| 32 | 6768 |
| 33 | -6980 |
| 34 | 8509 |
| 35 | -13389 |
| 36 | 16788 |
| 37 | -17609 |
| 38 | 23722 |
| 39 | -34720 |
| 40 | 40337 |
| 41 | -44863 |
| 42 | 63128 |
| 43 | -85430 |
| 44 | 95887 |
| 45 | -114037 |