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 | 3 |
| 2 | 6 |
| 3 | 16 |
| 4 | 40 |
| 5 | 100 |
| 6 | 252 |
| 7 | 632 |
| 8 | 1588 |
| 9 | 3988 |
| 10 | 10016 |
| 11 | 25156 |
| 12 | 63180 |
| 13 | 158680 |
| 14 | 398532 |
| 15 | 1000932 |
| 16 | 2513888 |
| 17 | 6313748 |
| 18 | 15857276 |
| 19 | 39826296 |
| 20 | 100025620 |
| 21 | 251219060 |
| 22 | 630948512 |
| 23 | 1584656932 |
| 24 | 3979940588 |
| 25 | 9995808408 |
| 26 | 25104944036 |
| 27 | 63052250436 |
| 28 | 158358699360 |