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 | 1 |
| 2 | 3 |
| 3 | 11 |
| 4 | 45 |
| 5 | 189 |
| 6 | 799 |
| 7 | 3383 |
| 8 | 14329 |
| 9 | 60697 |
| 10 | 257115 |
| 11 | 1089155 |
| 12 | 4613733 |
| 13 | 19544085 |
| 14 | 82790071 |
| 15 | 350704367 |
| 16 | 1485607537 |
| 17 | 6293134513 |
| 18 | 26658145587 |
| 19 | 112925716859 |
| 20 | 478361013021 |
| 21 | 2026369768941 |
| 22 | 8583840088783 |
| 23 | 36361730124071 |
| 24 | 154030760585065 |
| 25 | 652484772464329 |