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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 20 |
| 5 | 70 |
| 6 | 243 |
| 7 | 889 |
| 8 | 3276 |
| 9 | 12276 |
| 10 | 46435 |
| 11 | 176869 |
| 12 | 677022 |
| 13 | 2602197 |
| 14 | 10033212 |
| 15 | 38787495 |
| 16 | 150286400 |
| 17 | 583434322 |
| 18 | 2268848988 |
| 19 | 8836447021 |
| 20 | 34461894010 |
| 21 | 134564992002 |
| 22 | 526025788992 |
| 23 | 2058359779051 |
| 24 | 8061905110548 |
| 25 | 31602659997975 |