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 | 63 |
| 7 | 220 |
| 8 | 795 |
| 9 | 2942 |
| 10 | 11100 |
| 11 | 42547 |
| 12 | 165204 |
| 13 | 648423 |
| 14 | 2568522 |
| 15 | 10255044 |
| 16 | 41226054 |
| 17 | 166732446 |
| 18 | 677922831 |
| 19 | 2769487183 |
| 20 | 11362238976 |
| 21 | 46794199487 |
| 22 | 193387049685 |
| 23 | 801742251778 |
| 24 | 3333468469185 |
| 25 | 13896609698686 |
| 26 | 58073938493679 |
| 27 | 243238872937589 |
| 28 | 1020921149848044 |