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 | 1 |
| 3 | 3 |
| 4 | 6 |
| 5 | 19 |
| 6 | 49 |
| 7 | 163 |
| 8 | 472 |
| 9 | 1626 |
| 10 | 5034 |
| 11 | 17769 |
| 12 | 57474 |
| 13 | 206487 |
| 14 | 688881 |
| 15 | 2508195 |
| 16 | 8563020 |
| 17 | 31504240 |
| 18 | 109492960 |
| 19 | 406214878 |
| 20 | 1432030036 |
| 21 | 5349255726 |
| 22 | 19077934506 |
| 23 | 71672186953 |
| 24 | 258095737156 |
| 25 | 974311431094 |
| 26 | 3537275250214 |
| 27 | 13408623649893 |