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) |
|---|---|
| 0 | 1 |
| 1 | 45 |
| 2 | 675 |
| 3 | 5775 |
| 4 | 34650 |
| 5 | 162162 |
| 6 | 630630 |
| 7 | 2123550 |
| 8 | 6370650 |
| 9 | 17381650 |
| 10 | 43801758 |
| 11 | 103169430 |
| 12 | 229265400 |
| 13 | 484306200 |
| 14 | 978496200 |
| 15 | 1900457064 |
| 16 | 3563356995 |
| 17 | 6473226375 |
| 18 | 11428041625 |
| 19 | 19658764125 |
| 20 | 33026723730 |
| 21 | 54295634250 |
| 22 | 87501228750 |
| 23 | 138447123750 |
| 24 | 215362192500 |