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) |
|---|---|
| 1 | 1 |
| 2 | 10 |
| 3 | 81 |
| 4 | 620 |
| 5 | 4661 |
| 6 | 34830 |
| 7 | 259741 |
| 8 | 1935640 |
| 9 | 14421321 |
| 10 | 107436050 |
| 11 | 800355401 |
| 12 | 5962269060 |
| 13 | 44415937981 |
| 14 | 330876267670 |
| 15 | 2464859855061 |
| 16 | 18361949464880 |
| 17 | 136787157402641 |
| 18 | 1018994534193690 |
| 19 | 7590989351286721 |
| 20 | 56548997363187100 |