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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 9 |
| 6 | 27 |
| 7 | 63 |
| 8 | 147 |
| 9 | 343 |
| 10 | 735 |
| 11 | 1575 |
| 12 | 3375 |
| 13 | 6975 |
| 14 | 14415 |
| 15 | 29791 |
| 16 | 60543 |
| 17 | 123039 |
| 18 | 250047 |
| 19 | 504063 |
| 20 | 1016127 |
| 21 | 2048383 |
| 22 | 4112895 |
| 23 | 8258175 |
| 24 | 16581375 |
| 25 | 33227775 |
| 26 | 66585855 |
| 27 | 133432831 |
| 28 | 267126783 |
| 29 | 534776319 |
| 30 | 1070599167 |
| 31 | 2142244863 |
| 32 | 4286583807 |
| 33 | 8577357823 |
| 34 | 17158905855 |
| 35 | 34326194175 |
| 36 | 68669157375 |