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 | 14 |
| 5 | 51 |
| 6 | 202 |
| 7 | 876 |
| 8 | 4139 |
| 9 | 21146 |
| 10 | 115974 |
| 11 | 678569 |
| 12 | 4213596 |
| 13 | 27644436 |
| 14 | 190899321 |
| 15 | 1382958544 |
| 16 | 10480142146 |
| 17 | 82864869803 |
| 18 | 682076806158 |
| 19 | 5832742205056 |
| 20 | 51724158235371 |
| 21 | 474869816156750 |
| 22 | 4506715738447322 |
| 23 | 44152005855084345 |