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 | 40 |
| 2 | 1600 |
| 3 | 1296 |
| 4 | 5856 |
| 5 | 18564 |
| 6 | 50096 |
| 7 | 145200 |
| 8 | 453420 |
| 9 | 1403184 |
| 10 | 4038800 |
| 11 | 12177100 |
| 12 | 36992544 |
| 13 | 110036104 |
| 14 | 332138592 |
| 15 | 989787144 |
| 16 | 2977771420 |
| 17 | 8964400760 |
| 18 | 26737629576 |
| 19 | 80548970652 |
| 20 | 241336844800 |
| 21 | 723444785800 |
| 22 | 2175007306820 |