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 | 11 |
| 3 | 31 |
| 4 | 79 |
| 5 | 191 |
| 6 | 5119 |
| 7 | 245759 |
| 8 | 524287 |
| 9 | 1114111 |
| 10 | 3758096383 |
| 11 | 1618481116086271 |
| 12 | 653980173926178609468673073657929531391 |
| 13 | 5359447279004780799548150067050349330431 |