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 | 4 |
| 3 | 3 |
| 4 | 6 |
| 5 | 9 |
| 6 | 16 |
| 7 | 36 |
| 8 | 85 |
| 9 | 210 |
| 10 | 586 |
| 11 | 1914 |
| 12 | 6930 |
| 13 | 28178 |
| 14 | 125440 |
| 15 | 603350 |
| 16 | 3083410 |
| 17 | 17362239 |
| 18 | 112403052 |
| 19 | 820563290 |
| 20 | 6632950912 |
| 21 | 58209665965 |
| 22 | 544071039000 |
| 23 | 5353538904357 |
| 24 | 58523908575096 |
| 25 | 730174875609318 |
| 26 | 10274727352967428 |
| 27 | 159586345364505768 |