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 | 2 |
| 3 | 6 |
| 4 | 20 |
| 5 | 67 |
| 6 | 222 |
| 7 | 728 |
| 8 | 2368 |
| 9 | 7653 |
| 10 | 24602 |
| 11 | 78730 |
| 12 | 250956 |
| 13 | 797159 |
| 14 | 2524342 |
| 15 | 7971612 |
| 16 | 25110584 |
| 17 | 78918985 |
| 18 | 247518642 |
| 19 | 774840974 |
| 20 | 2421378052 |
| 21 | 7554699531 |
| 22 | 23535794702 |
| 23 | 73222472416 |
| 24 | 227512682160 |
| 25 | 706073841197 |
| 26 | 2188828907722 |
| 27 | 6778308875538 |
| 28 | 20970393083708 |
| 29 | 64817578622383 |