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 | 5 |
| 2 | 46 |
| 3 | 485 |
| 4 | 5626 |
| 5 | 69062 |
| 6 | 882540 |
| 7 | 11614437 |
| 8 | 156343330 |
| 9 | 2142556130 |
| 10 | 29791689148 |
| 11 | 419260001030 |
| 12 | 5960334608788 |
| 13 | 85469709312860 |
| 14 | 1234797737654296 |
| 15 | 17955907741675749 |
| 16 | 262607675818816050 |
| 17 | 3860239468267647914 |
| 18 | 57002176852356800700 |
| 19 | 845159480056345448610 |