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) |
|---|---|
| 4 | 25 |
| 5 | 454 |
| 6 | 3818 |
| 7 | 21420 |
| 8 | 92805 |
| 9 | 335152 |
| 10 | 1055944 |
| 11 | 2990020 |
| 12 | 7767357 |
| 13 | 18789070 |
| 14 | 42797602 |
| 15 | 92588216 |
| 16 | 191542842 |
| 17 | 381000192 |
| 18 | 731941256 |
| 19 | 1363109096 |
| 20 | 2468549141 |
| 21 | 4358716470 |
| 22 | 7520830306 |
| 23 | 12706161124 |
| 24 | 21054530855 |
| 25 | 34269633840 |
| 26 | 54863015040 |
| 27 | 86489873580 |
| 28 | 134406530985 |