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 | 10 |
| 2 | 76 |
| 3 | 568 |
| 4 | 4240 |
| 5 | 31648 |
| 6 | 236224 |
| 7 | 1763200 |
| 8 | 13160704 |
| 9 | 98232832 |
| 10 | 733219840 |
| 11 | 5472827392 |
| 12 | 40849739776 |
| 13 | 304906608640 |
| 14 | 2275853910016 |
| 15 | 16987204845568 |
| 16 | 126794223124480 |
| 17 | 946404965613568 |
| 18 | 7064062832410624 |
| 19 | 52726882796830720 |