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 | 7 |
| 3 | 23 |
| 4 | 79 |
| 5 | 241 |
| 6 | 727 |
| 7 | 2179 |
| 8 | 6553 |
| 9 | 19681 |
| 10 | 59029 |
| 11 | 177131 |
| 12 | 531383 |
| 13 | 1594301 |
| 14 | 4782961 |
| 15 | 14348891 |
| 16 | 43046623 |
| 17 | 129140153 |
| 18 | 387420479 |
| 19 | 1162261453 |
| 20 | 3486784393 |
| 21 | 10460353199 |
| 22 | 31381059607 |
| 23 | 94143178807 |
| 24 | 282429536453 |
| 25 | 847288609423 |