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 | 7 |
| 5 | 25 |
| 6 | 108 |
| 7 | 492 |
| 8 | 2431 |
| 9 | 12371 |
| 10 | 65169 |
| 11 | 350792 |
| 12 | 1926372 |
| 13 | 10744924 |
| 14 | 60762760 |
| 15 | 347653944 |
| 16 | 2009690895 |
| 17 | 11723100775 |
| 18 | 68937782355 |
| 19 | 408323229930 |
| 20 | 2434289046255 |
| 21 | 14598011263089 |
| 22 | 88011196469040 |
| 23 | 533216750567280 |
| 24 | 3245004785069892 |
| 25 | 19829768942544276 |
| 26 | 121639211516546668 |