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 | 5 |
| 3 | 16 |
| 4 | 48 |
| 5 | 164 |
| 6 | 559 |
| 7 | 1952 |
| 8 | 6872 |
| 9 | 24520 |
| 10 | 88006 |
| 11 | 318444 |
| 12 | 1158944 |
| 13 | 4241688 |
| 14 | 15598973 |
| 15 | 57620596 |
| 16 | 213680472 |
| 17 | 795270644 |
| 18 | 2969483214 |
| 19 | 11121038100 |
| 20 | 41763779054 |
| 21 | 157235683780 |
| 22 | 593355907790 |
| 23 | 2243975358216 |
| 24 | 8503404201874 |
| 25 | 32283434698908 |
| 26 | 122779218918272 |
| 27 | 467713035691608 |