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 | 1 |
| 2 | 2 |
| 3 | 6 |
| 4 | 18 |
| 5 | 58 |
| 6 | 186 |
| 7 | 614 |
| 8 | 2034 |
| 9 | 6818 |
| 10 | 22970 |
| 11 | 77858 |
| 12 | 264970 |
| 13 | 905294 |
| 14 | 3102434 |
| 15 | 10661370 |
| 16 | 36722642 |
| 17 | 126752218 |
| 18 | 438294018 |
| 19 | 1518032598 |
| 20 | 5265341314 |
| 21 | 18286911130 |
| 22 | 63586988434 |
| 23 | 221342104842 |
| 24 | 771235606050 |
| 25 | 2689688538646 |
| 26 | 9388096331642 |