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 | 509 |
| 2 | 18150 |
| 3 | 204630 |
| 4 | 1225230 |
| 5 | 4985070 |
| 6 | 15717750 |
| 7 | 41436870 |
| 8 | 95750430 |
| 9 | 200038110 |
| 10 | 385991430 |
| 11 | 698516790 |
| 12 | 1199001390 |
| 13 | 1968942030 |
| 14 | 3113936790 |
| 15 | 4768039590 |
| 16 | 7098477630 |
| 17 | 10310731710 |
| 18 | 14653979430 |
| 19 | 20426901270 |