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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | -5 |
| 6 | 15 |
| 7 | -35 |
| 8 | 71 |
| 9 | -126 |
| 10 | 205 |
| 11 | -330 |
| 12 | 511 |
| 13 | -715 |
| 14 | 966 |
| 15 | -1370 |
| 16 | 1891 |
| 17 | -2380 |
| 18 | 2949 |
| 19 | -3876 |
| 20 | 5051 |
| 21 | -6020 |
| 22 | 6985 |
| 23 | -8855 |
| 24 | 11207 |
| 25 | -12655 |
| 26 | 14235 |
| 27 | -17676 |
| 28 | 21442 |
| 29 | -23751 |
| 30 | 26260 |
| 31 | -31465 |
| 32 | 37851 |
| 33 | -41250 |
| 34 | 43996 |
| 35 | -52400 |
| 36 | 62350 |
| 37 | -66045 |
| 38 | 69939 |
| 39 | -82966 |
| 40 | 96511 |
| 41 | -101270 |