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 | 7 |
| 2 | 49 |
| 3 | 241 |
| 4 | 1171 |
| 5 | 5917 |
| 6 | 30067 |
| 7 | 151981 |
| 8 | 767377 |
| 9 | 3877045 |
| 10 | 19592047 |
| 11 | 98998267 |
| 12 | 500220187 |
| 13 | 2527540111 |
| 14 | 12771357967 |
| 15 | 64532102977 |
| 16 | 326072549563 |
| 17 | 1647603384079 |
| 18 | 8325132536305 |
| 19 | 42065847045655 |
| 20 | 212553428463613 |
| 21 | 1074005709153595 |