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 | 27 |
| 2 | 385 |
| 3 | 4004 |
| 4 | 34398 |
| 5 | 259896 |
| 6 | 1790712 |
| 7 | 11511720 |
| 8 | 70114902 |
| 9 | 409003595 |
| 10 | 2303105805 |
| 11 | 12593413560 |
| 12 | 67173369900 |
| 13 | 350777861280 |
| 14 | 1798432526880 |
| 15 | 9073909567440 |
| 16 | 45140379405030 |
| 17 | 221768094898350 |
| 18 | 1077403874372826 |
| 19 | 5182007298602904 |
| 20 | 24699073588138180 |
| 21 | 116759256962107760 |