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 | 456 |
| 2 | 1668 |
| 3 | 6220 |
| 4 | 23341 |
| 5 | 87752 |
| 6 | 330274 |
| 7 | 1244135 |
| 8 | 4688684 |
| 9 | 17678240 |
| 10 | 66670133 |
| 11 | 251457191 |
| 12 | 948433758 |
| 13 | 3577222198 |
| 14 | 13491914845 |
| 15 | 50884787739 |
| 16 | 191905944304 |
| 17 | 723728206116 |
| 18 | 2729294349873 |
| 19 | 10292348908806 |
| 20 | 38812294765020 |