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 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 26 |
| 6 | 91 |
| 7 | 246 |
| 8 | 589 |
| 9 | 1468 |
| 10 | 4226 |
| 11 | 13311 |
| 12 | 41471 |
| 13 | 122864 |
| 14 | 351184 |
| 15 | 1001876 |
| 16 | 2920957 |
| 17 | 8698612 |
| 18 | 26070130 |
| 19 | 77707056 |
| 20 | 229959130 |
| 21 | 679050870 |
| 22 | 2011457295 |
| 23 | 5986185690 |
| 24 | 17866178695 |
| 25 | 53343031301 |
| 26 | 159149943668 |
| 27 | 474683353849 |
| 28 | 1416730630936 |
| 29 | 4233405443596 |