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 | 1 |
| 3 | 2 |
| 4 | 6 |
| 5 | 19 |
| 6 | 60 |
| 7 | 189 |
| 8 | 595 |
| 9 | 1873 |
| 10 | 5896 |
| 11 | 18560 |
| 12 | 58425 |
| 13 | 183916 |
| 14 | 578949 |
| 15 | 1822473 |
| 16 | 5736961 |
| 17 | 18059374 |
| 18 | 56849086 |
| 19 | 178955183 |
| 20 | 563332848 |
| 21 | 1773314929 |
| 22 | 5582216355 |
| 23 | 17572253481 |
| 24 | 55315679788 |
| 25 | 174128175064 |
| 26 | 548137914373 |
| 27 | 1725482812088 |