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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 12 |
| 6 | 30 |
| 7 | 79 |
| 8 | 213 |
| 9 | 584 |
| 10 | 1628 |
| 11 | 4600 |
| 12 | 13138 |
| 13 | 37871 |
| 14 | 110043 |
| 15 | 321978 |
| 16 | 947813 |
| 17 | 2805104 |
| 18 | 8341608 |
| 19 | 24912004 |
| 20 | 74686460 |
| 21 | 224694128 |
| 22 | 678143656 |
| 23 | 2052640752 |
| 24 | 6229616730 |
| 25 | 18952875247 |
| 26 | 57792705415 |
| 27 | 176596786934 |
| 28 | 540679385663 |