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) |
|---|---|
| 2 | 0 |
| 3 | 4 |
| 4 | 16 |
| 5 | 49 |
| 6 | 137 |
| 7 | 369 |
| 8 | 978 |
| 9 | 2574 |
| 10 | 6754 |
| 11 | 17699 |
| 12 | 46355 |
| 13 | 121379 |
| 14 | 317796 |
| 15 | 832024 |
| 16 | 2178292 |
| 17 | 5702869 |
| 18 | 14930333 |
| 19 | 39088149 |
| 20 | 102334134 |
| 21 | 267914274 |
| 22 | 701408710 |
| 23 | 1836311879 |
| 24 | 4807526951 |
| 25 | 12586268999 |
| 26 | 32951280072 |
| 27 | 86267571244 |
| 28 | 225851433688 |
| 29 | 591286729849 |
| 30 | 1548008755889 |