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 | 3 |
| 3 | 7 |
| 4 | 15 |
| 5 | 43 |
| 6 | 168 |
| 7 | 626 |
| 8 | 2005 |
| 9 | 6245 |
| 10 | 22266 |
| 11 | 87365 |
| 12 | 328727 |
| 13 | 1154975 |
| 14 | 4086410 |
| 15 | 15464587 |
| 16 | 60368094 |
| 17 | 229327457 |
| 18 | 847539610 |
| 19 | 3174058754 |
| 20 | 12277874065 |
| 21 | 47912709420 |
| 22 | 184171945435 |
| 23 | 701491726600 |
| 24 | 2700878181660 |
| 25 | 10556457650417 |
| 26 | 41330116314628 |