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 | 0 |
| 2 | 1 |
| 3 | 0 |
| 4 | 2 |
| 5 | 2 |
| 6 | 8 |
| 7 | 8 |
| 8 | 34 |
| 9 | 60 |
| 10 | 203 |
| 11 | 553 |
| 12 | 2063 |
| 13 | 7359 |
| 14 | 30811 |
| 15 | 127416 |
| 16 | 541644 |
| 17 | 2235677 |
| 18 | 8966371 |
| 19 | 34413747 |
| 20 | 126465849 |
| 21 | 443858877 |
| 22 | 1490702752 |
| 23 | 4796609651 |
| 24 | 14821521743 |
| 25 | 44071296447 |
| 26 | 126388352322 |
| 27 | 350298687803 |
| 28 | 940211047828 |
| 29 | 2448320130626 |
| 30 | 6196158876181 |