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 | 260 |
| 3 | 6570 |
| 4 | 66576 |
| 5 | 390650 |
| 6 | 1708200 |
| 7 | 5764850 |
| 8 | 17043520 |
| 9 | 43105851 |
| 10 | 101569000 |
| 11 | 214359002 |
| 12 | 437404320 |
| 13 | 815730890 |
| 14 | 1498861000 |
| 15 | 2566570500 |
| 16 | 4363141376 |
| 17 | 6975757730 |
| 18 | 11207521260 |
| 19 | 16983563402 |
| 20 | 26007914400 |
| 21 | 37875064500 |
| 22 | 55733340520 |
| 23 | 78310985810 |
| 24 | 111975926400 |
| 25 | 152597656875 |