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) |
|---|---|
| 1 | 0 |
| 2 | 1 |
| 3 | 4 |
| 4 | 11 |
| 5 | 29 |
| 6 | 81 |
| 7 | 235 |
| 8 | 685 |
| 9 | 1986 |
| 10 | 5739 |
| 11 | 16577 |
| 12 | 47904 |
| 13 | 138472 |
| 14 | 400285 |
| 15 | 1157071 |
| 16 | 3344567 |
| 17 | 9667590 |
| 18 | 27944604 |
| 19 | 80775310 |
| 20 | 233485250 |
| 21 | 674901117 |
| 22 | 1950836005 |
| 23 | 5638990526 |
| 24 | 16299788815 |
| 25 | 47115369056 |
| 26 | 136189372297 |
| 27 | 393662311506 |
| 28 | 1137900943868 |
| 29 | 3289160582291 |
| 30 | 9507486039274 |