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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 3 |
| 5 | 7 |
| 6 | 15 |
| 7 | 34 |
| 8 | 78 |
| 9 | 191 |
| 10 | 493 |
| 11 | 1324 |
| 12 | 3626 |
| 13 | 10032 |
| 14 | 27808 |
| 15 | 77045 |
| 16 | 213273 |
| 17 | 590475 |
| 18 | 1637117 |
| 19 | 4550836 |
| 20 | 12692866 |
| 21 | 35532414 |
| 22 | 99830094 |
| 23 | 281412535 |
| 24 | 795601139 |
| 25 | 2254966896 |
| 26 | 6405076658 |
| 27 | 18227600051 |
| 28 | 51960277037 |
| 29 | 148352016215 |
| 30 | 424186720927 |
| 31 | 1214602291322 |