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 | 16 |
| 2 | 144 |
| 3 | 1240 |
| 4 | 10656 |
| 5 | 91816 |
| 6 | 793584 |
| 7 | 6880120 |
| 8 | 59823936 |
| 9 | 521638216 |
| 10 | 4560526224 |
| 11 | 39970994200 |
| 12 | 351149013216 |
| 13 | 3091621642216 |
| 14 | 27274838966064 |
| 15 | 241075504183480 |
| 16 | 2134495165562496 |
| 17 | 18928981513351816 |
| 18 | 168109033806481104 |
| 19 | 1494966905748847960 |
| 20 | 13310586963663775776 |