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 | 9 |
| 3 | 40 |
| 4 | 130 |
| 5 | 355 |
| 6 | 871 |
| 7 | 1994 |
| 8 | 4360 |
| 9 | 9245 |
| 10 | 19205 |
| 11 | 39356 |
| 12 | 79934 |
| 13 | 161415 |
| 14 | 324755 |
| 15 | 651870 |
| 16 | 1306596 |
| 17 | 2616609 |
| 18 | 5237265 |
| 19 | 10479280 |
| 20 | 20964090 |
| 21 | 41934571 |
| 22 | 83876479 |
| 23 | 167761330 |
| 24 | 335532160 |
| 25 | 671075045 |
| 26 | 1342162141 |
| 27 | 2684337764 |
| 28 | 5368690550 |