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 | 1 |
| 2 | 4 |
| 3 | 12 |
| 4 | 32 |
| 5 | 110 |
| 6 | 288 |
| 7 | 1092 |
| 8 | 2560 |
| 9 | 9072 |
| 10 | 26400 |
| 11 | 84700 |
| 12 | 165888 |
| 13 | 797160 |
| 14 | 2384928 |
| 15 | 6019200 |
| 16 | 15728640 |
| 17 | 64533700 |
| 18 | 141087744 |
| 19 | 580765248 |
| 20 | 1246080000 |
| 21 | 4823425152 |
| 22 | 14758128000 |
| 23 | 46070066188 |
| 24 | 85996339200 |
| 25 | 385087175000 |
| 26 | 1270928131200 |
| 27 | 3474144608256 |
| 28 | 8810420097024 |