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 | 1 |
| 2 | 3 |
| 3 | 9 |
| 4 | 18 |
| 5 | 60 |
| 6 | 117 |
| 7 | 371 |
| 8 | 747 |
| 9 | 2199 |
| 10 | 4697 |
| 11 | 12735 |
| 12 | 28571 |
| 13 | 72815 |
| 14 | 169176 |
| 15 | 412440 |
| 16 | 978086 |
| 17 | 2316754 |
| 18 | 5547293 |
| 19 | 12909723 |
| 20 | 30966639 |
| 21 | 71357601 |
| 22 | 170636159 |
| 23 | 391242623 |
| 24 | 930120982 |
| 25 | 2128073530 |
| 26 | 5023630830 |
| 27 | 11486060090 |
| 28 | 26918052717 |
| 29 | 61539213693 |
| 30 | 143227189518 |