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 | 13 |
| 2 | 23 |
| 3 | 43 |
| 4 | 83 |
| 5 | 163 |
| 6 | 643 |
| 7 | 1283 |
| 8 | 10243 |
| 9 | 20483 |
| 10 | 1310723 |
| 11 | 5242883 |
| 12 | 335544323 |
| 13 | 1342177283 |
| 14 | 21474836483 |
| 15 | 85899345923 |
| 16 | 43980465111043 |
| 17 | 87960930222083 |
| 18 | 5629499534213123 |
| 19 | 22517998136852483 |
| 20 | 1441151880758558723 |