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 | 4 |
| 1 | 32 |
| 2 | 284 |
| 3 | 2552 |
| 4 | 22964 |
| 5 | 206672 |
| 6 | 1860044 |
| 7 | 16740392 |
| 8 | 150663524 |
| 9 | 1355971712 |
| 10 | 12203745404 |
| 11 | 109833708632 |
| 12 | 988503377684 |
| 13 | 8896530399152 |
| 14 | 80068773592364 |
| 15 | 720618962331272 |
| 16 | 6485570660981444 |
| 17 | 58370135948832992 |
| 18 | 525331223539496924 |
| 19 | 4727981011855472312 |
| 20 | 42551829106699250804 |