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 | 1 |
| 1 | 54 |
| 2 | 945 |
| 3 | 9240 |
| 4 | 62370 |
| 5 | 324324 |
| 6 | 1387386 |
| 7 | 5096520 |
| 8 | 16563690 |
| 9 | 48668620 |
| 10 | 131405274 |
| 11 | 330142176 |
| 12 | 779502360 |
| 13 | 1743502320 |
| 14 | 3718285560 |
| 15 | 7601828256 |
| 16 | 14966099379 |
| 17 | 28482196050 |
| 18 | 52568991475 |
| 19 | 94362067800 |
| 20 | 165133618650 |
| 21 | 282337298100 |
| 22 | 472506635250 |
| 23 | 775303893000 |
| 24 | 1249100716500 |