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) |
|---|---|
| 9 | 1 |
| 10 | 4 |
| 11 | 19 |
| 12 | 66 |
| 13 | 219 |
| 14 | 645 |
| 15 | 1813 |
| 16 | 4802 |
| 17 | 12265 |
| 18 | 30198 |
| 19 | 72396 |
| 20 | 169231 |
| 21 | 387707 |
| 22 | 871989 |
| 23 | 1930868 |
| 24 | 4215615 |
| 25 | 9091410 |
| 26 | 19389327 |
| 27 | 40944999 |
| 28 | 85691893 |
| 29 | 177898521 |
| 30 | 366614456 |
| 31 | 750494796 |
| 32 | 1526979694 |
| 33 | 3089556090 |
| 34 | 6219191608 |
| 35 | 12460307373 |
| 36 | 24856533408 |
| 37 | 49387348955 |
| 38 | 97765283686 |
| 39 | 192870793594 |
| 40 | 379287172272 |