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 | 3 |
| 2 | 14 |
| 3 | 52 |
| 4 | 216 |
| 5 | 848 |
| 6 | 3424 |
| 7 | 13632 |
| 8 | 54656 |
| 9 | 218368 |
| 10 | 873984 |
| 11 | 3494912 |
| 12 | 13981696 |
| 13 | 55922688 |
| 14 | 223698944 |
| 15 | 894779392 |
| 16 | 3579150336 |
| 17 | 14316535808 |
| 18 | 57266274304 |
| 19 | 229064835072 |
| 20 | 916259864576 |
| 21 | 3665038409728 |
| 22 | 14660155736064 |
| 23 | 58640618749952 |