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 | 3 |
| 1 | 4 |
| 2 | 8 |
| 3 | 20 |
| 4 | 44 |
| 5 | 92 |
| 6 | 188 |
| 7 | 380 |
| 8 | 856 |
| 9 | 2148 |
| 10 | 5024 |
| 11 | 17616 |
| 12 | 58768 |
| 13 | 176320 |
| 14 | 755904 |
| 15 | 3305920 |
| 16 | 13885184 |
| 17 | 69634816 |
| 18 | 348174336 |
| 19 | 2385273856 |
| 20 | 14652403712 |
| 21 | 102566830080 |
| 22 | 849285738496 |
| 23 | 6035962949632 |
| 24 | 44017806979072 |
| 25 | 308166534991872 |
| 26 | 2380768960708608 |
| 27 | 23410894780694528 |