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 | 8 |
| 3 | 58 |
| 4 | 444 |
| 5 | 3708 |
| 6 | 33984 |
| 7 | 341136 |
| 8 | 3733920 |
| 9 | 44339040 |
| 10 | 568356480 |
| 11 | 7827719040 |
| 12 | 115336085760 |
| 13 | 1810992556800 |
| 14 | 30196376985600 |
| 15 | 532953524275200 |
| 16 | 9927928075161600 |
| 17 | 194677319705702400 |
| 18 | 4008789120817152000 |
| 19 | 86495828444928000000 |
| 20 | 1951566265951948800000 |
| 21 | 45958933902500720640000 |