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 | 1 |
| 2 | 2 |
| 3 | 5 |
| 4 | 13 |
| 5 | 37 |
| 6 | 111 |
| 7 | 345 |
| 8 | 1104 |
| 9 | 3611 |
| 10 | 12016 |
| 11 | 40548 |
| 12 | 138414 |
| 13 | 477076 |
| 14 | 1657956 |
| 15 | 5802920 |
| 16 | 20436910 |
| 17 | 72369903 |
| 18 | 257518806 |
| 19 | 920333307 |
| 20 | 3302003826 |
| 21 | 11888979066 |
| 22 | 42944410207 |
| 23 | 155576009845 |
| 24 | 565127618392 |
| 25 | 2057903975752 |
| 26 | 7510967300206 |