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 | 9 |
| 2 | 45 |
| 3 | 174 |
| 4 | 576 |
| 5 | 1701 |
| 6 | 4614 |
| 7 | 11709 |
| 8 | 28125 |
| 9 | 64525 |
| 10 | 142353 |
| 11 | 303552 |
| 12 | 628251 |
| 13 | 1266273 |
| 14 | 2492352 |
| 15 | 4801578 |
| 16 | 9071973 |
| 17 | 16837893 |
| 18 | 30744649 |
| 19 | 55296000 |
| 20 | 98070633 |
| 21 | 171683463 |
| 22 | 296919081 |
| 23 | 507695670 |
| 24 | 858866880 |
| 25 | 1438391232 |
| 26 | 2386178649 |
| 27 | 3923081006 |
| 28 | 6395198049 |
| 29 | 10341173376 |
| 30 | 16593811467 |