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 | 27 |
| 4 | 79 |
| 5 | 255 |
| 6 | 843 |
| 7 | 2763 |
| 8 | 8903 |
| 9 | 28215 |
| 10 | 88195 |
| 11 | 272739 |
| 12 | 836607 |
| 13 | 2550735 |
| 14 | 7742267 |
| 15 | 23423355 |
| 16 | 70695991 |
| 17 | 213005415 |
| 18 | 640982259 |
| 19 | 1927141011 |
| 20 | 5790335855 |
| 21 | 17389881855 |
| 22 | 52209491371 |
| 23 | 156712360107 |
| 24 | 470313240999 |
| 25 | 1411308821655 |
| 26 | 4234698216803 |
| 27 | 12705705263043 |
| 28 | 38120471232223 |