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 | 0 |
| 2 | 1 |
| 3 | 13 |
| 4 | 177 |
| 5 | 2371 |
| 6 | 31622 |
| 7 | 421696 |
| 8 | 5623413 |
| 9 | 74989420 |
| 10 | 999999999 |
| 11 | 1000000000 |
| 12 | 13335214321 |
| 13 | 177827941003 |
| 14 | 2371373705661 |
| 15 | 31622776601683 |
| 16 | 421696503428582 |
| 17 | 5623413251903490 |
| 18 | 74989420933245582 |
| 19 | 999999999999999999 |
| 20 | 1000000000000000000 |
| 21 | 13335214321633240256 |
| 22 | 177827941003892280122 |