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 | 2 |
| 4 | 6 |
| 5 | 17 |
| 6 | 46 |
| 7 | 128 |
| 8 | 372 |
| 9 | 1109 |
| 10 | 3349 |
| 11 | 10221 |
| 12 | 31527 |
| 13 | 98178 |
| 14 | 308179 |
| 15 | 973911 |
| 16 | 3096044 |
| 17 | 9894393 |
| 18 | 31770247 |
| 19 | 102444145 |
| 20 | 331594081 |
| 21 | 1077022622 |
| 22 | 3509197080 |
| 23 | 11466710630 |
| 24 | 37567784437 |
| 25 | 123380796192 |
| 26 | 406120349756 |
| 27 | 1339571374103 |