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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 23 |
| 6 | 63 |
| 7 | 155 |
| 8 | 448 |
| 9 | 1152 |
| 10 | 3452 |
| 11 | 9157 |
| 12 | 28176 |
| 13 | 76514 |
| 14 | 240318 |
| 15 | 664718 |
| 16 | 2122557 |
| 17 | 5959052 |
| 18 | 19289899 |
| 19 | 54828151 |
| 20 | 179538447 |
| 21 | 515641437 |
| 22 | 1705240090 |
| 23 | 4941294887 |
| 24 | 16481424379 |
| 25 | 48127922888 |
| 26 | 161736798007 |
| 27 | 475487875843 |
| 28 | 1608541737898 |
| 29 | 4757151493126 |
| 30 | 16188528696215 |