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 | 5 |
| 2 | 30 |
| 3 | 229 |
| 4 | 2165 |
| 5 | 24576 |
| 6 | 326515 |
| 7 | 4976315 |
| 8 | 85630914 |
| 9 | 1642623355 |
| 10 | 34762642871 |
| 11 | 804650577600 |
| 12 | 20224019536825 |
| 13 | 548535471681029 |
| 14 | 15969883030969470 |
| 15 | 496754110707779461 |
| 16 | 16441934503725675485 |
| 17 | 576991048929859964160 |
| 18 | 21399021201104749243099 |
| 19 | 836326710446071005267035 |