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 | 2 |
| 3 | 6 |
| 4 | 20 |
| 5 | 61 |
| 6 | 185 |
| 7 | 577 |
| 8 | 1788 |
| 9 | 5540 |
| 10 | 17165 |
| 11 | 52991 |
| 12 | 163600 |
| 13 | 504983 |
| 14 | 1557494 |
| 15 | 4800848 |
| 16 | 14791118 |
| 17 | 45548176 |
| 18 | 140205732 |
| 19 | 431413253 |
| 20 | 1326980704 |
| 21 | 4080331096 |
| 22 | 12542893726 |
| 23 | 38546177015 |
| 24 | 118428377799 |
| 25 | 363772262171 |
| 26 | 1117147291580 |
| 27 | 3430089594015 |