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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 0 |
| 5 | 1 |
| 6 | 5 |
| 7 | 19 |
| 8 | 66 |
| 9 | 218 |
| 10 | 700 |
| 11 | 2218 |
| 12 | 6997 |
| 13 | 22064 |
| 14 | 69662 |
| 15 | 220395 |
| 16 | 699090 |
| 17 | 2224114 |
| 18 | 7098773 |
| 19 | 22733498 |
| 20 | 73048903 |
| 21 | 235504760 |
| 22 | 761689193 |
| 23 | 2471105355 |
| 24 | 8040439771 |
| 25 | 26235143469 |
| 26 | 85831045851 |
| 27 | 281519068056 |
| 28 | 925596771195 |
| 29 | 3050264328190 |
| 30 | 10074150332305 |
| 31 | 33341934697311 |
| 32 | 110571437129989 |