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 | 3 |
| 2 | 19 |
| 3 | 147 |
| 4 | 1251 |
| 5 | 11253 |
| 6 | 104959 |
| 7 | 1004307 |
| 8 | 9793891 |
| 9 | 96918753 |
| 10 | 970336269 |
| 11 | 9807518757 |
| 12 | 99912156111 |
| 13 | 1024622952993 |
| 14 | 10567623342519 |
| 15 | 109527728400147 |
| 16 | 1140076177397091 |
| 17 | 11911997404064793 |
| 18 | 124879633548031009 |
| 19 | 1313106114867738897 |
| 20 | 13844511065506477501 |