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) |
|---|---|
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 2 |
| 6 | 6 |
| 7 | 12 |
| 8 | 35 |
| 9 | 70 |
| 10 | 204 |
| 11 | 408 |
| 12 | 1189 |
| 13 | 2378 |
| 14 | 6930 |
| 15 | 13860 |
| 16 | 40391 |
| 17 | 80782 |
| 18 | 235416 |
| 19 | 470832 |
| 20 | 1372105 |
| 21 | 2744210 |
| 22 | 7997214 |
| 23 | 15994428 |
| 24 | 46611179 |
| 25 | 93222358 |
| 26 | 271669860 |
| 27 | 543339720 |
| 28 | 1583407981 |
| 29 | 3166815962 |
| 30 | 9228778026 |
| 31 | 18457556052 |
| 32 | 53789260175 |
| 33 | 107578520350 |