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 | 9 |
| 2 | 47 |
| 3 | 187 |
| 4 | 630 |
| 5 | 1898 |
| 6 | 5282 |
| 7 | 13866 |
| 8 | 34831 |
| 9 | 84575 |
| 10 | 199977 |
| 11 | 462973 |
| 12 | 1053804 |
| 13 | 2365704 |
| 14 | 5250660 |
| 15 | 11543700 |
| 16 | 25177005 |
| 17 | 54539205 |
| 18 | 117456115 |
| 19 | 251676495 |
| 20 | 536892146 |
| 21 | 1140875254 |
| 22 | 2415947382 |
| 23 | 5100306062 |
| 24 | 10737455195 |
| 25 | 22548620283 |