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 | 3 |
| 3 | 8 |
| 4 | 23 |
| 5 | 63 |
| 6 | 197 |
| 7 | 588 |
| 8 | 1892 |
| 9 | 6140 |
| 10 | 20734 |
| 11 | 71472 |
| 12 | 254090 |
| 13 | 923900 |
| 14 | 3446572 |
| 15 | 13149295 |
| 16 | 51316445 |
| 17 | 204556612 |
| 18 | 832467052 |
| 19 | 3455533022 |
| 20 | 14621598811 |
| 21 | 63023667027 |
| 22 | 276559371189 |
| 23 | 1234802595648 |
| 24 | 5606647482646 |
| 25 | 25875459311317 |
| 26 | 121324797470067 |
| 27 | 577692044073205 |