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 | 3 |
| 1 | 4 |
| 2 | 8 |
| 3 | 20 |
| 4 | 54 |
| 5 | 132 |
| 6 | 312 |
| 7 | 720 |
| 8 | 1620 |
| 9 | 3672 |
| 10 | 8162 |
| 11 | 17864 |
| 12 | 38874 |
| 13 | 84018 |
| 14 | 180504 |
| 15 | 386094 |
| 16 | 821642 |
| 17 | 1742538 |
| 18 | 3681132 |
| 19 | 7754078 |
| 20 | 16290048 |
| 21 | 34136030 |
| 22 | 71378570 |
| 23 | 148948140 |
| 24 | 310248242 |
| 25 | 645155198 |
| 26 | 1339484198 |
| 27 | 2777105130 |
| 28 | 5750079048 |
| 29 | 11891268402 |
| 30 | 24563311310 |
| 31 | 50685770168 |
| 32 | 104484802058 |