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 | 27 |
| 2 | 174 |
| 3 | 594 |
| 4 | 3078 |
| 5 | 13140 |
| 6 | 58752 |
| 7 | 253416 |
| 8 | 1090344 |
| 9 | 4637904 |
| 10 | 19604352 |
| 11 | 82332384 |
| 12 | 343986912 |
| 13 | 1430547456 |
| 14 | 5925418752 |
| 15 | 24456120000 |
| 16 | 100618925568 |
| 17 | 412797979584 |
| 18 | 1689208728576 |
| 19 | 6896384506176 |
| 20 | 28095875422848 |
| 21 | 114241910041536 |