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 | 3 |
| 2 | 15 |
| 3 | 117 |
| 4 | 1227 |
| 5 | 16053 |
| 6 | 251955 |
| 7 | 4613997 |
| 8 | 96566667 |
| 9 | 2273672133 |
| 10 | 59482039395 |
| 11 | 1711735382877 |
| 12 | 53737315411707 |
| 13 | 1827584253650613 |
| 14 | 66936582030410835 |
| 15 | 2626714554845111757 |
| 16 | 109948916113808074347 |
| 17 | 4889877314768678051493 |