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 | 2 |
| 2 | 4 |
| 3 | 14 |
| 4 | 47 |
| 5 | 184 |
| 6 | 761 |
| 7 | 3314 |
| 8 | 14997 |
| 9 | 69886 |
| 10 | 333884 |
| 11 | 1626998 |
| 12 | 8067786 |
| 13 | 40580084 |
| 14 | 206734083 |
| 15 | 1064666724 |
| 16 | 5536480877 |
| 17 | 29036188788 |
| 18 | 153450351924 |
| 19 | 816503772830 |
| 20 | 4371551433888 |