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 | 3 |
| 1 | 2 |
| 2 | 6 |
| 3 | 20 |
| 4 | 50 |
| 5 | 132 |
| 6 | 354 |
| 7 | 940 |
| 8 | 2498 |
| 9 | 6644 |
| 10 | 17666 |
| 11 | 46972 |
| 12 | 124898 |
| 13 | 332100 |
| 14 | 883042 |
| 15 | 2347980 |
| 16 | 6243202 |
| 17 | 16600468 |
| 18 | 44140098 |
| 19 | 117367068 |
| 20 | 312075170 |
| 21 | 829797604 |
| 22 | 2206404514 |
| 23 | 5866756972 |
| 24 | 15599513666 |
| 25 | 41478593332 |
| 26 | 110290214274 |