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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 21 |
| 5 | 51 |
| 6 | 105 |
| 7 | 231 |
| 8 | 471 |
| 9 | 975 |
| 10 | 1965 |
| 11 | 4011 |
| 12 | 8031 |
| 13 | 16221 |
| 14 | 32475 |
| 15 | 65205 |
| 16 | 130485 |
| 17 | 261555 |
| 18 | 523131 |
| 19 | 1047417 |
| 20 | 2094957 |
| 21 | 4191975 |
| 22 | 8384229 |
| 23 | 16772835 |
| 24 | 33545715 |
| 25 | 67100115 |
| 26 | 134200785 |
| 27 | 268418001 |
| 28 | 536837061 |
| 29 | 1073707971 |
| 30 | 2147415981 |