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 | 3 |
| 2 | 18 |
| 3 | 192 |
| 4 | 2730 |
| 5 | 42408 |
| 6 | 673698 |
| 7 | 10760592 |
| 8 | 172097370 |
| 9 | 2753276088 |
| 10 | 44051309778 |
| 11 | 704816584992 |
| 12 | 11277048051210 |
| 13 | 180432700116168 |
| 14 | 2886922928640258 |
| 15 | 46190765770153392 |
| 16 | 739052247984440250 |
| 17 | 11824835950442034648 |
| 18 | 189197375137965657138 |
| 19 | 3027158001931410345792 |