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 | -2 |
| 2 | 1 |
| 3 | -1 |
| 4 | 2 |
| 5 | -3 |
| 6 | 7 |
| 7 | -10 |
| 8 | 13 |
| 9 | -21 |
| 10 | 26 |
| 11 | -33 |
| 12 | 53 |
| 13 | -80 |
| 14 | 127 |
| 15 | -193 |
| 16 | 254 |
| 17 | -355 |
| 18 | 527 |
| 19 | -764 |
| 20 | 1149 |
| 21 | -1699 |
| 22 | 2436 |
| 23 | -3563 |
| 24 | 5133 |
| 25 | -7352 |
| 26 | 10819 |
| 27 | -15863 |
| 28 | 23162 |
| 29 | -33887 |
| 30 | 48969 |
| 31 | -70936 |
| 32 | 103571 |
| 33 | -150715 |
| 34 | 219844 |
| 35 | -320973 |
| 36 | 466641 |
| 37 | -679232 |
| 38 | 988627 |
| 39 | -1437185 |
| 40 | 2094446 |
| 41 | -3052743 |