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 | -1 |
| 3 | 1 |
| 4 | -2 |
| 5 | 3 |
| 6 | -4 |
| 7 | 5 |
| 8 | -7 |
| 9 | 10 |
| 10 | -12 |
| 11 | 15 |
| 12 | -20 |
| 13 | 26 |
| 14 | -32 |
| 15 | 39 |
| 16 | -50 |
| 17 | 63 |
| 18 | -76 |
| 19 | 92 |
| 20 | -114 |
| 21 | 140 |
| 22 | -168 |
| 23 | 201 |
| 24 | -244 |
| 25 | 295 |
| 26 | -350 |
| 27 | 415 |
| 28 | -496 |
| 29 | 591 |
| 30 | -696 |
| 31 | 818 |
| 32 | -967 |
| 33 | 1140 |
| 34 | -1332 |
| 35 | 1554 |
| 36 | -1820 |
| 37 | 2126 |
| 38 | -2468 |
| 39 | 2861 |
| 40 | -3324 |
| 41 | 3855 |
| 42 | -4448 |
| 43 | 5126 |
| 44 | -5916 |
| 45 | 6816 |
| 46 | -7824 |
| 47 | 8970 |
| 48 | -10292 |
| 49 | 11793 |
| 50 | -13471 |
| 51 | 15372 |
| 52 | -17548 |