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 | 3 |
| 3 | 11 |
| 4 | 42 |
| 5 | 176 |
| 6 | 808 |
| 7 | 4015 |
| 8 | 21423 |
| 9 | 122035 |
| 10 | 738424 |
| 11 | 4725200 |
| 12 | 31854056 |
| 13 | 225472729 |
| 14 | 1670849235 |
| 15 | 12929089547 |
| 16 | 104227219082 |
| 17 | 873524820380 |
| 18 | 7596906788456 |
| 19 | 68442869865191 |
| 20 | 637789899261963 |
| 21 | 6138617062823371 |
| 22 | 60945644655192264 |
| 23 | 623410514987315252 |
| 24 | 6562725963582441936 |