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) |
|---|---|
| 3 | 1 |
| 4 | 3 |
| 5 | 9 |
| 6 | 34 |
| 7 | 125 |
| 8 | 473 |
| 9 | 1779 |
| 10 | 6732 |
| 11 | 25492 |
| 12 | 96927 |
| 13 | 369463 |
| 14 | 1412700 |
| 15 | 5415117 |
| 16 | 20807502 |
| 17 | 80120350 |
| 18 | 309106496 |
| 19 | 1194609429 |
| 20 | 4624160156 |
| 21 | 17925278497 |
| 22 | 69578272204 |
| 23 | 270401326899 |
| 24 | 1052036082719 |
| 25 | 4097343156323 |
| 26 | 15973179953261 |
| 27 | 62325892264031 |
| 28 | 243392644741599 |