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 | 1 |
| 2 | 6 |
| 3 | 31 |
| 4 | 188 |
| 5 | 1510 |
| 6 | 16106 |
| 7 | 217938 |
| 8 | 3577624 |
| 9 | 68952495 |
| 10 | 1524157870 |
| 11 | 37974983321 |
| 12 | 1052320304212 |
| 13 | 32089921353308 |
| 14 | 1067586804710258 |
| 15 | 38470738234990580 |
| 16 | 1492501011869912496 |
| 17 | 62015249735222969325 |
| 18 | 2747431806313734355830 |
| 19 | 129267455591507496073315 |