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 | 3 |
| 3 | 10 |
| 4 | 35 |
| 5 | 126 |
| 6 | 77 |
| 7 | 1716 |
| 8 | 6435 |
| 9 | 24310 |
| 10 | 46189 |
| 11 | 352716 |
| 12 | 676039 |
| 13 | 5200300 |
| 14 | 10029150 |
| 15 | 5170584 |
| 16 | 300540195 |
| 17 | 1166803110 |
| 18 | 756261275 |
| 19 | 17672631900 |
| 20 | 6892326441 |
| 21 | 89709645740 |
| 22 | 526024740930 |
| 23 | 4116715363800 |
| 24 | 2687300306925 |
| 25 | 63205303218876 |
| 26 | 123979633237026 |
| 27 | 973469712824056 |
| 28 | 136583760727865 |
| 29 | 15033633249770520 |
| 30 | 29566145391215356 |