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 | 5 |
| 3 | 20 |
| 4 | 85 |
| 5 | 385 |
| 6 | 1836 |
| 7 | 9120 |
| 8 | 46805 |
| 9 | 246675 |
| 10 | 1328925 |
| 11 | 7292688 |
| 12 | 40652780 |
| 13 | 229698220 |
| 14 | 1313175880 |
| 15 | 7585060680 |
| 16 | 44212723797 |
| 17 | 259808593975 |
| 18 | 1537840085775 |
| 19 | 9162371040900 |
| 20 | 54913015836525 |
| 21 | 330888232445505 |
| 22 | 2003659057873200 |
| 23 | 12187811305300800 |
| 24 | 74444226847892460 |
| 25 | 456458831442283860 |