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 | 5 |
| 3 | 30 |
| 4 | 174 |
| 5 | 1015 |
| 6 | 5915 |
| 7 | 34476 |
| 8 | 200940 |
| 9 | 1171165 |
| 10 | 6826049 |
| 11 | 39785130 |
| 12 | 231884730 |
| 13 | 1351523251 |
| 14 | 7877254775 |
| 15 | 45912005400 |
| 16 | 267594777624 |
| 17 | 1559656660345 |
| 18 | 9090345184445 |
| 19 | 52982414446326 |
| 20 | 308804141493510 |
| 21 | 1799842434514735 |
| 22 | 10490250465594899 |
| 23 | 61141660359054660 |
| 24 | 356359711688733060 |