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 | 1 |
| 2 | 3 |
| 3 | 19 |
| 4 | 217 |
| 5 | 3821 |
| 6 | 95761 |
| 7 | 3214975 |
| 8 | 137501505 |
| 9 | 7226764921 |
| 10 | 455941716481 |
| 11 | 33983083953611 |
| 12 | 2954163633223969 |
| 13 | 296027886705639973 |
| 14 | 33823026186790043841 |
| 15 | 4363561123325076879991 |
| 16 | 630392564294402819207041 |