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 | 4 |
| 3 | 27 |
| 4 | 257 |
| 5 | 3156 |
| 6 | 47442 |
| 7 | 843352 |
| 8 | 17300943 |
| 9 | 402210240 |
| 10 | 10448526896 |
| 11 | 299925224064 |
| 12 | 9426724628301 |
| 13 | 321959469056512 |
| 14 | 11872685912032350 |
| 15 | 470132249600142336 |
| 16 | 19895288956008203963 |
| 17 | 896055382220853362688 |
| 18 | 42793946679993786078108 |
| 19 | 2160123874888094765056000 |