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 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 3 |
| 6 | 6 |
| 7 | 17 |
| 8 | 48 |
| 9 | 96 |
| 10 | 271 |
| 11 | 765 |
| 12 | 1530 |
| 13 | 4319 |
| 14 | 12192 |
| 15 | 24384 |
| 16 | 68833 |
| 17 | 194307 |
| 18 | 388614 |
| 19 | 1097009 |
| 20 | 3096720 |
| 21 | 6193440 |
| 22 | 17483311 |
| 23 | 49353213 |
| 24 | 98706426 |
| 25 | 278635967 |
| 26 | 786554688 |
| 27 | 1573109376 |
| 28 | 4440692161 |
| 29 | 12535521795 |
| 30 | 25071043590 |
| 31 | 70772438609 |
| 32 | 199781794032 |
| 33 | 399563588064 |