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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 6 |
| 6 | 26 |
| 7 | 94 |
| 8 | 306 |
| 9 | 934 |
| 10 | 2732 |
| 11 | 7752 |
| 12 | 21488 |
| 13 | 58432 |
| 14 | 156288 |
| 15 | 411904 |
| 16 | 1071104 |
| 17 | 2750976 |
| 18 | 6984704 |
| 19 | 17545216 |
| 20 | 43634688 |
| 21 | 107511808 |
| 22 | 262602752 |
| 23 | 636223488 |
| 24 | 1529741312 |
| 25 | 3652059136 |
| 26 | 8660975616 |
| 27 | 20412104704 |
| 28 | 47826599936 |
| 29 | 111446851584 |
| 30 | 258360737792 |
| 31 | 596044152832 |