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 | 0 |
| 1 | 1 |
| 2 | 3 |
| 3 | 22 |
| 4 | 323 |
| 5 | 7906 |
| 6 | 290262 |
| 7 | 14919430 |
| 8 | 1022475715 |
| 9 | 90094491994 |
| 10 | 9923239949978 |
| 11 | 1335853771297750 |
| 12 | 215797095378591542 |
| 13 | 41198645313603207990 |
| 14 | 9176288655853717238830 |
| 15 | 2358300288047799986966722 |