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 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 14 |
| 5 | 44 |
| 6 | 152 |
| 7 | 514 |
| 8 | 1866 |
| 9 | 6884 |
| 10 | 26137 |
| 11 | 100442 |
| 12 | 390592 |
| 13 | 1526272 |
| 14 | 5989223 |
| 15 | 23548688 |
| 16 | 92727898 |
| 17 | 365445200 |
| 18 | 1441195226 |
| 19 | 5686268314 |
| 20 | 22444465311 |
| 21 | 88622259788 |
| 22 | 350040069245 |
| 23 | 1383007946774 |
| 24 | 5465854718664 |
| 25 | 21607909105528 |
| 26 | 85444555330132 |
| 27 | 337962745845558 |
| 28 | 1337094537703089 |