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 | 10 |
| 2 | 75 |
| 3 | 450 |
| 4 | 2365 |
| 5 | 11202 |
| 6 | 49020 |
| 7 | 200900 |
| 8 | 779650 |
| 9 | 2886970 |
| 10 | 10263057 |
| 11 | 35193340 |
| 12 | 116865525 |
| 13 | 376994900 |
| 14 | 1184596410 |
| 15 | 3633899268 |
| 16 | 10904012980 |
| 17 | 32058245900 |
| 18 | 92484729375 |
| 19 | 262142323480 |
| 20 | 730865120997 |
| 21 | 2006375900880 |
| 22 | 5428232646875 |
| 23 | 14485462366250 |
| 24 | 38155463010810 |