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) |
|---|---|
| 1 | 1 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 12 |
| 6 | 35 |
| 7 | 122 |
| 8 | 390 |
| 9 | 1320 |
| 10 | 4631 |
| 11 | 16185 |
| 12 | 57707 |
| 13 | 208348 |
| 14 | 756840 |
| 15 | 2775012 |
| 16 | 10246206 |
| 17 | 38043339 |
| 18 | 142045387 |
| 19 | 532888840 |
| 20 | 2007554241 |
| 21 | 7592537590 |
| 22 | 28814794105 |
| 23 | 109702322730 |
| 24 | 418868083725 |
| 25 | 1603584623355 |
| 26 | 6154156653687 |
| 27 | 23671591739306 |
| 28 | 91242219125712 |
| 29 | 352378515196920 |
| 30 | 1363360128627380 |