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) |
|---|---|
| 2 | 1 |
| 3 | 4 |
| 4 | 17 |
| 5 | 68 |
| 6 | 270 |
| 7 | 1064 |
| 8 | 4181 |
| 9 | 16404 |
| 10 | 64322 |
| 11 | 252184 |
| 12 | 988890 |
| 13 | 3879016 |
| 14 | 15222236 |
| 15 | 59764048 |
| 16 | 234755661 |
| 17 | 922591156 |
| 18 | 3627586618 |
| 19 | 14270426936 |
| 20 | 56164324206 |
| 21 | 221147123768 |
| 22 | 871147242116 |
| 23 | 3433076812336 |
| 24 | 13534723031298 |
| 25 | 53380361293960 |
| 26 | 210606884630932 |