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 | 20 |
| 3 | 68 |
| 4 | 208 |
| 5 | 592 |
| 6 | 1600 |
| 7 | 4160 |
| 8 | 10496 |
| 9 | 25856 |
| 10 | 62464 |
| 11 | 148480 |
| 12 | 348160 |
| 13 | 806912 |
| 14 | 1851392 |
| 15 | 4210688 |
| 16 | 9502720 |
| 17 | 21299200 |
| 18 | 47448064 |
| 19 | 105119744 |
| 20 | 231735296 |
| 21 | 508559360 |
| 22 | 1111490560 |
| 23 | 2420113408 |
| 24 | 5251268608 |
| 25 | 11358175232 |
| 26 | 24494735360 |