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 | 159 |
| 4 | 3039 |
| 5 | 89439 |
| 6 | 3718239 |
| 7 | 206931039 |
| 8 | 14838252639 |
| 9 | 1331657196639 |
| 10 | 146181741036639 |
| 11 | 19266392807916639 |
| 12 | 3002019319241196639 |
| 13 | 545863051930098156639 |
| 14 | 114546679900210059756639 |
| 15 | 27474742723487400843756639 |
| 16 | 7469448066579203294091756639 |
| 17 | 2284713285166428266627979756639 |