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 | 0 |
| 2 | 1 |
| 3 | 5 |
| 4 | 18 |
| 5 | 59 |
| 6 | 190 |
| 7 | 618 |
| 8 | 2047 |
| 9 | 6908 |
| 10 | 23703 |
| 11 | 82488 |
| 12 | 290499 |
| 13 | 1033398 |
| 14 | 3707837 |
| 15 | 13402681 |
| 16 | 48760350 |
| 17 | 178405139 |
| 18 | 656043838 |
| 19 | 2423307027 |
| 20 | 8987427446 |
| 21 | 33453694465 |
| 22 | 124936258104 |
| 23 | 467995871753 |
| 24 | 1757900019076 |
| 25 | 6619846420527 |
| 26 | 24987199492678 |
| 27 | 94520750408681 |