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 | 3 |
| 2 | 9 |
| 3 | 26 |
| 4 | 72 |
| 5 | 195 |
| 6 | 520 |
| 7 | 1368 |
| 8 | 3560 |
| 9 | 9184 |
| 10 | 23520 |
| 11 | 59860 |
| 12 | 151536 |
| 13 | 381840 |
| 14 | 958256 |
| 15 | 2396192 |
| 16 | 5972736 |
| 17 | 14845040 |
| 18 | 36801792 |
| 19 | 91021056 |
| 20 | 224642304 |
| 21 | 553347072 |
| 22 | 1360598016 |
| 23 | 3340024384 |
| 24 | 8186748160 |
| 25 | 20038426368 |
| 26 | 48983457024 |
| 27 | 119593531904 |
| 28 | 291657627648 |
| 29 | 710522702592 |