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 | 7 |
| 3 | 70 |
| 4 | 868 |
| 5 | 11746 |
| 6 | 169022 |
| 7 | 2533895 |
| 8 | 39156244 |
| 9 | 619261762 |
| 10 | 9974917309 |
| 11 | 163078496420 |
| 12 | 2699109217420 |
| 13 | 45136794135853 |
| 14 | 761492594770649 |
| 15 | 12944937176754422 |
| 16 | 221518183089901621 |
| 17 | 3812823547509811611 |
| 18 | 65966582592220602621 |
| 19 | 1146568019260356348978 |