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 | 22 |
| 5 | 88 |
| 6 | 363 |
| 7 | 1507 |
| 8 | 6241 |
| 9 | 25721 |
| 10 | 105485 |
| 11 | 430767 |
| 12 | 1752945 |
| 13 | 7113095 |
| 14 | 28797292 |
| 15 | 116368938 |
| 16 | 469531170 |
| 17 | 1892133076 |
| 18 | 7617145998 |
| 19 | 30638026074 |
| 20 | 123145086046 |
| 21 | 494663313342 |
| 22 | 1985995240464 |
| 23 | 7969941119476 |
| 24 | 31971818819844 |
| 25 | 128214549263032 |
| 26 | 514024475597524 |
| 27 | 2060262910065740 |
| 28 | 8255954041620260 |