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 | 4 |
| 2 | 18 |
| 3 | 64 |
| 4 | 219 |
| 5 | 676 |
| 6 | 2030 |
| 7 | 5736 |
| 8 | 15793 |
| 9 | 41864 |
| 10 | 108430 |
| 11 | 273240 |
| 12 | 675526 |
| 13 | 1634780 |
| 14 | 3891960 |
| 15 | 9108872 |
| 16 | 21018870 |
| 17 | 47815572 |
| 18 | 107446898 |
| 19 | 238524144 |
| 20 | 523812125 |
| 21 | 1138233100 |
| 22 | 2449710880 |
| 23 | 5223395480 |
| 24 | 11042278208 |