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 | 0 |
| 1 | 2 |
| 2 | 6 |
| 3 | 16 |
| 4 | 38 |
| 5 | 98 |
| 6 | 244 |
| 7 | 614 |
| 8 | 1542 |
| 9 | 3872 |
| 10 | 9726 |
| 11 | 24426 |
| 12 | 61348 |
| 13 | 154078 |
| 14 | 386974 |
| 15 | 971904 |
| 16 | 2440982 |
| 17 | 6130642 |
| 18 | 15397396 |
| 19 | 38671286 |
| 20 | 97124758 |
| 21 | 243933408 |
| 22 | 612650254 |
| 23 | 1538699994 |
| 24 | 3864517572 |
| 25 | 9705918062 |
| 26 | 24376870766 |
| 27 | 61223660096 |
| 28 | 153766108518 |