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 | 1 |
| 2 | 6 |
| 3 | 50 |
| 4 | 484 |
| 5 | 5105 |
| 6 | 56928 |
| 7 | 660112 |
| 8 | 7878940 |
| 9 | 96159476 |
| 10 | 1194532794 |
| 11 | 15053992178 |
| 12 | 191993403476 |
| 13 | 2473358617150 |
| 14 | 32137897641232 |
| 15 | 420698195672700 |
| 16 | 5542894551818268 |
| 17 | 73447821835338348 |
| 18 | 978178443083177880 |
| 19 | 13086377223959022952 |
| 20 | 175785879063917657688 |