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) |
|---|---|
| 3 | 3 |
| 4 | 12 |
| 5 | 50 |
| 6 | 195 |
| 7 | 735 |
| 8 | 2716 |
| 9 | 9912 |
| 10 | 35850 |
| 11 | 128865 |
| 12 | 461175 |
| 13 | 1645215 |
| 14 | 5855941 |
| 15 | 20810153 |
| 16 | 73870748 |
| 17 | 262029364 |
| 18 | 929031504 |
| 19 | 3293120337 |
| 20 | 11672207262 |
| 21 | 41373395052 |
| 22 | 146674116501 |
| 23 | 520093043437 |
| 24 | 1844704839175 |
| 25 | 6544970763175 |
| 26 | 23229252652125 |