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 | 13 |
| 2 | 105 |
| 3 | 853 |
| 4 | 7185 |
| 5 | 62173 |
| 6 | 547065 |
| 7 | 4861093 |
| 8 | 43437345 |
| 9 | 389373613 |
| 10 | 3496550025 |
| 11 | 31429887733 |
| 12 | 282673677105 |
| 13 | 2543086531453 |
| 14 | 22882895970585 |
| 15 | 205921649672773 |
| 16 | 1853172776742465 |
| 17 | 16677944639119693 |
| 18 | 150098449994264745 |
| 19 | 1350870791159320213 |
| 20 | 12157760826488569425 |
| 21 | 109419465968670562333 |