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 | 3 |
| 2 | 9 |
| 3 | 30 |
| 4 | 102 |
| 5 | 361 |
| 6 | 1308 |
| 7 | 4819 |
| 8 | 17970 |
| 9 | 67614 |
| 10 | 256156 |
| 11 | 975742 |
| 12 | 3733255 |
| 13 | 14336290 |
| 14 | 55224880 |
| 15 | 213298817 |
| 16 | 825741010 |
| 17 | 3203142338 |
| 18 | 12447523904 |
| 19 | 48448301960 |
| 20 | 188838707898 |
| 21 | 736985826174 |
| 22 | 2879588370517 |
| 23 | 11263139964066 |
| 24 | 44096779183060 |
| 25 | 172797721166402 |