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 | 2 |
| 1 | 4 |
| 2 | 9 |
| 3 | 22 |
| 4 | 57 |
| 5 | 154 |
| 6 | 429 |
| 7 | 1222 |
| 8 | 3537 |
| 9 | 10354 |
| 10 | 30549 |
| 11 | 90622 |
| 12 | 269817 |
| 13 | 805354 |
| 14 | 2407869 |
| 15 | 7207222 |
| 16 | 21588897 |
| 17 | 64701154 |
| 18 | 193972389 |
| 19 | 581655022 |
| 20 | 1744440777 |
| 21 | 5232273754 |
| 22 | 15694724109 |
| 23 | 47079978022 |
| 24 | 141231545457 |
| 25 | 423677859154 |
| 26 | 1271000023029 |