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 | 55 |
| 7 | 138 |
| 8 | 349 |
| 9 | 904 |
| 10 | 2377 |
| 11 | 6323 |
| 12 | 16993 |
| 13 | 46036 |
| 14 | 125625 |
| 15 | 344973 |
| 16 | 952565 |
| 17 | 2643257 |
| 18 | 7366942 |
| 19 | 20613366 |
| 20 | 57884187 |
| 21 | 163071852 |
| 22 | 460769168 |
| 23 | 1305466309 |
| 24 | 3707928596 |
| 25 | 10555941648 |
| 26 | 30115379589 |
| 27 | 86087330322 |
| 28 | 246541672062 |
| 29 | 707274898726 |
| 30 | 2032285666846 |