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) |
|---|---|
| 1 | 0 |
| 2 | 2 |
| 3 | 15 |
| 4 | 148 |
| 5 | 1785 |
| 6 | 26106 |
| 7 | 449701 |
| 8 | 8927192 |
| 9 | 200847681 |
| 10 | 5053782070 |
| 11 | 140679853941 |
| 12 | 4293235236324 |
| 13 | 142553671807729 |
| 14 | 5116962926162738 |
| 15 | 197459475792232725 |
| 16 | 8152354312656732976 |
| 17 | 358585728464893234305 |
| 18 | 16741214317684425260142 |
| 19 | 826842457727306803110997 |
| 20 | 43073414675338753123113980 |