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 | 6 |
| 4 | 23 |
| 5 | 106 |
| 6 | 565 |
| 7 | 3399 |
| 8 | 22678 |
| 9 | 165646 |
| 10 | 1311334 |
| 11 | 11161529 |
| 12 | 101478038 |
| 13 | 980157177 |
| 14 | 10011461983 |
| 15 | 107712637346 |
| 16 | 1216525155129 |
| 17 | 14380174353934 |
| 18 | 177440071258827 |
| 19 | 2280166654498540 |
| 20 | 30450785320307436 |
| 21 | 421820687108853017 |
| 22 | 6050801956624661417 |
| 23 | 89738550379292147192 |