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 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 9 |
| 6 | 22 |
| 7 | 56 |
| 8 | 152 |
| 9 | 428 |
| 10 | 1257 |
| 11 | 3827 |
| 12 | 12023 |
| 13 | 38975 |
| 14 | 129801 |
| 15 | 443833 |
| 16 | 1554849 |
| 17 | 5572334 |
| 18 | 20409121 |
| 19 | 76283610 |
| 20 | 290737945 |
| 21 | 1128730320 |
| 22 | 4460079331 |
| 23 | 17924115817 |
| 24 | 73207479057 |
| 25 | 303691230784 |
| 26 | 1278796858227 |
| 27 | 5462983288161 |
| 28 | 23664467118878 |
| 29 | 103895077228910 |