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 | 2 |
| 1 | 17 |
| 2 | 130 |
| 3 | 940 |
| 4 | 6550 |
| 5 | 44475 |
| 6 | 296250 |
| 7 | 1944375 |
| 8 | 12612500 |
| 9 | 81035000 |
| 10 | 516537500 |
| 11 | 3270615625 |
| 12 | 20591031250 |
| 13 | 128998328125 |
| 14 | 804673593750 |
| 15 | 5000444062500 |
| 16 | 30969644531250 |
| 17 | 191231146484375 |
| 18 | 1177627753906250 |
| 19 | 7234317013671875 |
| 20 | 44342955390625000 |
| 21 | 271252632343750000 |