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 | 2 |
| 3 | 7 |
| 4 | 24 |
| 5 | 84 |
| 6 | 313 |
| 7 | 1209 |
| 8 | 4769 |
| 9 | 19166 |
| 10 | 78253 |
| 11 | 323570 |
| 12 | 1352122 |
| 13 | 5701467 |
| 14 | 24229122 |
| 15 | 103663575 |
| 16 | 446163435 |
| 17 | 1930390329 |
| 18 | 8391341664 |
| 19 | 36630504952 |
| 20 | 160509484616 |
| 21 | 705750073063 |
| 22 | 3112865367660 |
| 23 | 13769327908980 |
| 24 | 61066953746400 |
| 25 | 271488240652950 |
| 26 | 1209671359828154 |