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 | 1 |
| 1 | 57 |
| 2 | 1596 |
| 3 | 29260 |
| 4 | 395010 |
| 5 | 4187106 |
| 6 | 36288252 |
| 7 | 264385836 |
| 8 | 1652411475 |
| 9 | 8996462475 |
| 10 | 43183019880 |
| 11 | 184509266760 |
| 12 | 707285522580 |
| 13 | 2448296039700 |
| 14 | 7694644696200 |
| 15 | 22057981462440 |
| 16 | 57902201338905 |
| 17 | 139646485582065 |
| 18 | 310325523515700 |
| 19 | 636983969321700 |