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 | 7 |
| 2 | 56 |
| 3 | 490 |
| 4 | 4550 |
| 5 | 44051 |
| 6 | 439824 |
| 7 | 4496388 |
| 8 | 46834095 |
| 9 | 495260150 |
| 10 | 5303177880 |
| 11 | 57385471962 |
| 12 | 626548297648 |
| 13 | 6893781417320 |
| 14 | 76362138282400 |
| 15 | 850867975145160 |
| 16 | 9530515916642385 |
| 17 | 107249427630005661 |
| 18 | 1211964598880990640 |
| 19 | 13747501038498835300 |