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 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 16 |
| 6 | 55 |
| 7 | 197 |
| 8 | 705 |
| 9 | 2563 |
| 10 | 9381 |
| 11 | 34563 |
| 12 | 128029 |
| 13 | 476347 |
| 14 | 1779107 |
| 15 | 6666752 |
| 16 | 25054585 |
| 17 | 94401460 |
| 18 | 356510371 |
| 19 | 1349182629 |
| 20 | 5115555725 |
| 21 | 19429832443 |
| 22 | 73916249353 |
| 23 | 281613780638 |
| 24 | 1074400168957 |
| 25 | 4104279704526 |
| 26 | 15697542046005 |
| 27 | 60106182177517 |
| 28 | 230394256650275 |
| 29 | 884024296630081 |
| 30 | 3395269379129779 |