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 | 20 |
| 3 | 96 |
| 4 | 432 |
| 5 | 1856 |
| 6 | 7744 |
| 7 | 31744 |
| 8 | 128768 |
| 9 | 519168 |
| 10 | 2085888 |
| 11 | 8364032 |
| 12 | 33501184 |
| 13 | 134103040 |
| 14 | 536625152 |
| 15 | 2146959360 |
| 16 | 8588820480 |
| 17 | 34357379072 |
| 18 | 137433972736 |
| 19 | 549745328128 |
| 20 | 2199001235456 |
| 21 | 8796046884864 |
| 22 | 35184275619840 |
| 23 | 140737287028736 |
| 24 | 562949533990912 |