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 | 1 |
| 1 | 0 |
| 2 | 1 |
| 3 | 1 |
| 4 | 5 |
| 5 | 6 |
| 6 | 27 |
| 7 | 47 |
| 8 | 169 |
| 9 | 406 |
| 10 | 1327 |
| 11 | 3790 |
| 12 | 12560 |
| 13 | 39919 |
| 14 | 136821 |
| 15 | 470589 |
| 16 | 1687981 |
| 17 | 6162696 |
| 18 | 23173374 |
| 19 | 88981796 |
| 20 | 349969596 |
| 21 | 1405386733 |
| 22 | 5764142220 |
| 23 | 24111709328 |
| 24 | 102825231702 |
| 25 | 446665313598 |
| 26 | 1975339030948 |
| 27 | 8888051121242 |
| 28 | 40667889052853 |
| 29 | 189126710033882 |
| 30 | 893526261542899 |