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 | 4 |
| 2 | 14 |
| 3 | 46 |
| 4 | 141 |
| 5 | 427 |
| 6 | 1282 |
| 7 | 3849 |
| 8 | 11553 |
| 9 | 34663 |
| 10 | 104001 |
| 11 | 312005 |
| 12 | 936017 |
| 13 | 2808053 |
| 14 | 8424161 |
| 15 | 25272487 |
| 16 | 75817463 |
| 17 | 227452391 |
| 18 | 682357183 |
| 19 | 2047071551 |
| 20 | 6141214658 |
| 21 | 18423643982 |
| 22 | 55270931959 |
| 23 | 165812795887 |
| 24 | 497438387665 |
| 25 | 1492315162999 |