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) |
|---|---|
| 3 | 0 |
| 4 | 5 |
| 5 | 18 |
| 6 | 44 |
| 7 | 116 |
| 8 | 331 |
| 9 | 932 |
| 10 | 2532 |
| 11 | 6720 |
| 12 | 17804 |
| 13 | 47280 |
| 14 | 125460 |
| 15 | 331736 |
| 16 | 874973 |
| 17 | 2305750 |
| 18 | 6075184 |
| 19 | 16001968 |
| 20 | 42130767 |
| 21 | 110885496 |
| 22 | 291792264 |
| 23 | 767776064 |
| 24 | 2020061968 |
| 25 | 5314529928 |
| 26 | 13981117152 |
| 27 | 36779372688 |
| 28 | 96751538581 |
| 29 | 254510051546 |
| 30 | 669494097852 |
| 31 | 1761102380100 |