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 | 9 |
| 3 | 134 |
| 4 | 1862 |
| 5 | 26251 |
| 6 | 369251 |
| 7 | 5196060 |
| 8 | 73113372 |
| 9 | 1028784997 |
| 10 | 14476099149 |
| 11 | 203694183170 |
| 12 | 2866194639170 |
| 13 | 40330419190351 |
| 14 | 567492063162119 |
| 15 | 7985219303802744 |
| 16 | 112360562315573112 |
| 17 | 1581033091723823881 |
| 18 | 22246823846444284881 |
| 19 | 313036566941955454910 |