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 | 2 |
| 2 | 4 |
| 3 | 9 |
| 4 | 20 |
| 5 | 47 |
| 6 | 110 |
| 7 | 264 |
| 8 | 634 |
| 9 | 1541 |
| 10 | 3754 |
| 11 | 9204 |
| 12 | 22622 |
| 13 | 55817 |
| 14 | 138026 |
| 15 | 342203 |
| 16 | 849984 |
| 17 | 2115245 |
| 18 | 5271970 |
| 19 | 13158944 |
| 20 | 32886338 |
| 21 | 82285031 |
| 22 | 206101422 |
| 23 | 516728937 |
| 24 | 1296664512 |
| 25 | 3256472235 |
| 26 | 8184526438 |
| 27 | 20584627358 |
| 28 | 51805243138 |
| 29 | 130456806425 |
| 30 | 328703655114 |