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 | 5 |
| 2 | 30 |
| 3 | 205 |
| 4 | 1555 |
| 5 | 12880 |
| 6 | 115155 |
| 7 | 1101705 |
| 8 | 11202680 |
| 9 | 120415755 |
| 10 | 1362057155 |
| 11 | 16151603830 |
| 12 | 200144023805 |
| 13 | 2584429030505 |
| 14 | 34691478901030 |
| 15 | 483040313859705 |
| 16 | 6963313750468055 |
| 17 | 103747357497925880 |
| 18 | 1595132080103893655 |