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 | 1 |
| 3 | 1 |
| 4 | 1 |
| 5 | 0 |
| 6 | -5 |
| 7 | -20 |
| 8 | -55 |
| 9 | -125 |
| 10 | -250 |
| 11 | -450 |
| 12 | -725 |
| 13 | -1000 |
| 14 | -1000 |
| 15 | 0 |
| 16 | 3625 |
| 17 | 13125 |
| 18 | 34375 |
| 19 | 76875 |
| 20 | 153750 |
| 21 | 278125 |
| 22 | 450000 |
| 23 | 621875 |
| 24 | 621875 |
| 25 | 0 |
| 26 | -2250000 |
| 27 | -8140625 |
| 28 | -21312500 |
| 29 | -47656250 |
| 30 | -95312500 |
| 31 | -172421875 |
| 32 | -278984375 |
| 33 | -385546875 |
| 34 | -385546875 |
| 35 | 0 |
| 36 | 1394921875 |