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) |
|---|---|
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 6 |
| 6 | 16 |
| 7 | 42 |
| 8 | 151 |
| 9 | 596 |
| 10 | 2605 |
| 11 | 12098 |
| 12 | 59166 |
| 13 | 297684 |
| 14 | 1538590 |
| 15 | 8109078 |
| 16 | 43476751 |
| 17 | 236474942 |
| 18 | 1302680941 |
| 19 | 7256842362 |
| 20 | 40832979283 |
| 21 | 231838418310 |
| 22 | 1327095781740 |
| 23 | 7653155567834 |
| 24 | 44434752082990 |
| 25 | 259600430870176 |
| 26 | 1525366978752096 |
| 27 | 9010312253993072 |
| 28 | 53485145730576790 |