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 | 0 |
| 2 | 0 |
| 3 | 1 |
| 4 | 1 |
| 5 | 1 |
| 6 | 2 |
| 7 | 6 |
| 8 | 17 |
| 9 | 44 |
| 10 | 112 |
| 11 | 304 |
| 12 | 918 |
| 13 | 3040 |
| 14 | 10623 |
| 15 | 38161 |
| 16 | 140074 |
| 17 | 528594 |
| 18 | 2068751 |
| 19 | 8436893 |
| 20 | 35813251 |
| 21 | 157448068 |
| 22 | 713084042 |
| 23 | 3315414747 |
| 24 | 15805117878 |
| 25 | 77273097114 |
| 26 | 387692392570 |
| 27 | 1996280632656 |
| 28 | 10542604575130 |
| 29 | 57034787751655 |
| 30 | 315649657181821 |