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 | 3 |
| 1 | 14 |
| 2 | 180 |
| 3 | 2240 |
| 4 | 21060 |
| 5 | 267988 |
| 6 | 3706920 |
| 7 | 38773952 |
| 8 | 459970056 |
| 9 | 6692483840 |
| 10 | 79425033660 |
| 11 | 800162860756 |
| 12 | 9101898907920 |
| 13 | 117326869641600 |
| 14 | 1596198064568400 |
| 15 | 20655000929239040 |
| 16 | 184885459808838660 |
| 17 | 2390210102271311936 |
| 18 | 33504016991491136160 |
| 19 | 344201347103878781440 |