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 | 9 |
| 3 | 49 |
| 4 | 210 |
| 5 | 765 |
| 6 | 2492 |
| 7 | 7434 |
| 8 | 20700 |
| 9 | 54420 |
| 10 | 136360 |
| 11 | 327789 |
| 12 | 760102 |
| 13 | 1707342 |
| 14 | 3728025 |
| 15 | 7935525 |
| 16 | 16507152 |
| 17 | 33624045 |
| 18 | 67186077 |
| 19 | 131891825 |
| 20 | 254710260 |
| 21 | 484474753 |
| 22 | 908538081 |
| 23 | 1681364124 |
| 24 | 3073166600 |
| 25 | 5551851375 |
| 26 | 9919925145 |
| 27 | 17541289017 |
| 28 | 30714092066 |
| 29 | 53279031420 |