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 | 36 |
| 4 | 354 |
| 5 | 4425 |
| 6 | 67171 |
| 7 | 1200304 |
| 8 | 24684612 |
| 9 | 574304985 |
| 10 | 14914341925 |
| 11 | 427675990236 |
| 12 | 13421957361110 |
| 13 | 457593884876401 |
| 14 | 16841089312342855 |
| 15 | 665478473553144000 |
| 16 | 28101527071305611528 |
| 17 | 1262899292504270591313 |
| 18 | 60182438244917445266889 |
| 19 | 3031284048960901518840700 |