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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 3 |
| 5 | 7 |
| 6 | 15 |
| 7 | 35 |
| 8 | 81 |
| 9 | 195 |
| 10 | 473 |
| 11 | 1170 |
| 12 | 2920 |
| 13 | 7378 |
| 14 | 18787 |
| 15 | 48242 |
| 16 | 124658 |
| 17 | 324095 |
| 18 | 846872 |
| 19 | 2223352 |
| 20 | 5861011 |
| 21 | 15508423 |
| 22 | 41173560 |
| 23 | 109648734 |