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 | 3 |
| 3 | 23 |
| 4 | 223 |
| 5 | 2800 |
| 6 | 42576 |
| 7 | 763220 |
| 8 | 15734388 |
| 9 | 366715248 |
| 10 | 9533817400 |
| 11 | 273549419552 |
| 12 | 8586984241870 |
| 13 | 292755986184548 |
| 14 | 10772849583399474 |
| 15 | 425587711650564816 |
| 16 | 17966217346985801150 |
| 17 | 807152054953801845760 |
| 18 | 38451365602113352159320 |
| 19 | 1936082850634342992601636 |