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 | 5 |
| 2 | 21 |
| 3 | 122 |
| 4 | 765 |
| 5 | 5000 |
| 6 | 34581 |
| 7 | 249152 |
| 8 | 1843485 |
| 9 | 14184320 |
| 10 | 111117141 |
| 11 | 890892032 |
| 12 | 7338139005 |
| 13 | 60554071040 |
| 14 | 518102719701 |
| 15 | 4409318285312 |
| 16 | 38356828343325 |
| 17 | 341939662684160 |
| 18 | 2933245707834261 |
| 19 | 28085287524564992 |
| 20 | 229163829314312445 |
| 21 | 2425706018857287680 |
| 22 | 18151248585662332821 |