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 | 8 |
| 5 | 17 |
| 6 | 39 |
| 7 | 97 |
| 8 | 261 |
| 9 | 756 |
| 10 | 2344 |
| 11 | 7738 |
| 12 | 27070 |
| 13 | 99946 |
| 14 | 388085 |
| 15 | 1579914 |
| 16 | 6725192 |
| 17 | 29860100 |
| 18 | 137991971 |
| 19 | 662439670 |
| 20 | 3297635881 |
| 21 | 16995183941 |
| 22 | 90547999761 |
| 23 | 498054983333 |
| 24 | 2824769922669 |
| 25 | 16500577556487 |
| 26 | 99166469633984 |
| 27 | 612564931889099 |
| 28 | 3885636053023492 |
| 29 | 25288452931575498 |