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 | 1 |
| 3 | 2 |
| 4 | 7 |
| 5 | 24 |
| 6 | 88 |
| 7 | 328 |
| 8 | 1235 |
| 9 | 4668 |
| 10 | 17675 |
| 11 | 66974 |
| 12 | 253858 |
| 13 | 962352 |
| 14 | 3648397 |
| 15 | 13831870 |
| 16 | 52440191 |
| 17 | 198815196 |
| 18 | 753764564 |
| 19 | 2857736696 |
| 20 | 10834499599 |
| 21 | 41076702120 |
| 22 | 155733594211 |
| 23 | 590430871282 |
| 24 | 2238493367822 |
| 25 | 8486772670944 |
| 26 | 32175798041273 |