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 | 6 |
| 4 | 16 |
| 5 | 34 |
| 6 | 90 |
| 7 | 211 |
| 8 | 558 |
| 9 | 1371 |
| 10 | 3601 |
| 11 | 9209 |
| 12 | 24110 |
| 13 | 61740 |
| 14 | 157559 |
| 15 | 390832 |
| 16 | 946490 |
| 17 | 2206364 |
| 18 | 4948194 |
| 19 | 10591141 |
| 20 | 21606125 |
| 21 | 41821936 |
| 22 | 76738813 |
| 23 | 133157386 |
| 24 | 218402867 |
| 25 | 338187004 |
| 26 | 494330780 |
| 27 | 681660841 |
| 28 | 886842587 |
| 29 | 1088201827 |