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 | 5 |
| 2 | 18 |
| 3 | 63 |
| 4 | 224 |
| 5 | 799 |
| 6 | 2846 |
| 7 | 10132 |
| 8 | 36073 |
| 9 | 128438 |
| 10 | 457304 |
| 11 | 1628224 |
| 12 | 5797263 |
| 13 | 20641062 |
| 14 | 73492179 |
| 15 | 261667749 |
| 16 | 931663897 |
| 17 | 3317174627 |
| 18 | 11810748015 |
| 19 | 42051982296 |
| 20 | 149725420655 |
| 21 | 533095002085 |
| 22 | 1898076358760 |
| 23 | 6758070980980 |
| 24 | 24062005289281 |
| 25 | 85672390859855 |