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 | 1 |
| 2 | 2 |
| 3 | 8 |
| 4 | 24 |
| 5 | 80 |
| 6 | 256 |
| 7 | 832 |
| 8 | 2688 |
| 9 | 8704 |
| 10 | 28160 |
| 11 | 91136 |
| 12 | 294912 |
| 13 | 954368 |
| 14 | 3088384 |
| 15 | 9994240 |
| 16 | 32342016 |
| 17 | 104660992 |
| 18 | 338690048 |
| 19 | 1096024064 |
| 20 | 3546808320 |
| 21 | 11477712896 |
| 22 | 37142659072 |
| 23 | 120196169728 |
| 24 | 388962975744 |
| 25 | 1258710630400 |