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 | 0 |
| 4 | 0 |
| 5 | 0 |
| 6 | 1 |
| 7 | 12 |
| 8 | 89 |
| 9 | 528 |
| 10 | 2755 |
| 11 | 13244 |
| 12 | 60214 |
| 13 | 263121 |
| 14 | 1116791 |
| 15 | 4637476 |
| 16 | 18936940 |
| 17 | 76327705 |
| 18 | 304520286 |
| 19 | 1205152900 |
| 20 | 4738962369 |
| 21 | 18540020091 |
| 22 | 72240167011 |
| 23 | 280579954028 |
| 24 | 1087033982059 |
| 25 | 4203231136230 |
| 26 | 16228518078010 |
| 27 | 62588797371361 |
| 28 | 241198478726775 |