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 | 12 |
| 2 | 88 |
| 3 | 552 |
| 4 | 3968 |
| 5 | 29112 |
| 6 | 218008 |
| 7 | 1650528 |
| 8 | 12582880 |
| 9 | 96324600 |
| 10 | 739228968 |
| 11 | 5681576176 |
| 12 | 43706415776 |
| 13 | 336396570496 |
| 14 | 2589969578592 |
| 15 | 19944309195072 |
| 16 | 153600126376320 |
| 17 | 1183021908352864 |
| 18 | 9111943178894368 |
| 19 | 70184192846874336 |