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) |
|---|---|
| 1 | 1 |
| 2 | 8 |
| 3 | 45 |
| 4 | 224 |
| 5 | 1045 |
| 6 | 4680 |
| 7 | 20377 |
| 8 | 86912 |
| 9 | 364905 |
| 10 | 1513160 |
| 11 | 6211909 |
| 12 | 25290720 |
| 13 | 102251773 |
| 14 | 410963336 |
| 15 | 1643288625 |
| 16 | 6541692416 |
| 17 | 25939798993 |
| 18 | 102503274120 |
| 19 | 403800061789 |
| 20 | 1586318259680 |
| 21 | 6216231359205 |
| 22 | 24304019419592 |
| 23 | 94826736906697 |
| 24 | 369285078314880 |
| 25 | 1435615286196025 |