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 | 10 |
| 2 | 2046 |
| 3 | 88572 |
| 4 | 1398100 |
| 5 | 12207030 |
| 6 | 72559410 |
| 7 | 329554456 |
| 8 | 1227133512 |
| 9 | 3922632450 |
| 10 | 11111111110 |
| 11 | 28531167060 |
| 12 | 67546215516 |
| 13 | 149346699502 |
| 14 | 311505013050 |
| 15 | 617839704240 |
| 16 | 1172812402960 |
| 17 | 2141993519226 |
| 18 | 3780494710542 |
| 19 | 6471681049900 |
| 20 | 10778947368420 |
| 21 | 17513875027110 |