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) |
|---|---|
| 0 | 6 |
| 1 | 27 |
| 2 | 111 |
| 3 | 447 |
| 4 | 1791 |
| 5 | 7167 |
| 6 | 28671 |
| 7 | 114687 |
| 8 | 458751 |
| 9 | 1835007 |
| 10 | 7340031 |
| 11 | 29360127 |
| 12 | 117440511 |
| 13 | 469762047 |
| 14 | 1879048191 |
| 15 | 7516192767 |
| 16 | 30064771071 |
| 17 | 120259084287 |
| 18 | 481036337151 |
| 19 | 1924145348607 |
| 20 | 7696581394431 |
| 21 | 30786325577727 |
| 22 | 123145302310911 |
| 23 | 492581209243647 |
| 24 | 1970324836974591 |