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 | 6 |
| 2 | 109 |
| 3 | 660 |
| 4 | 11989 |
| 5 | 72594 |
| 6 | 1318681 |
| 7 | 7984680 |
| 8 | 145042921 |
| 9 | 878242206 |
| 10 | 15953402629 |
| 11 | 96598657980 |
| 12 | 1754729246269 |
| 13 | 10624974135594 |
| 14 | 193004263686961 |
| 15 | 1168650556257360 |
| 16 | 21228714276319441 |
| 17 | 128540936214174006 |
| 18 | 2334965566131451549 |
| 19 | 14138334333002883300 |