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 | 18 |
| 5 | 57 |
| 6 | 190 |
| 7 | 654 |
| 8 | 2306 |
| 9 | 8290 |
| 10 | 30272 |
| 11 | 111973 |
| 12 | 418666 |
| 13 | 1579803 |
| 14 | 6008464 |
| 15 | 23009240 |
| 16 | 88645034 |
| 17 | 343334976 |
| 18 | 1336105472 |
| 19 | 5221667740 |
| 20 | 20485272152 |
| 21 | 80645855014 |
| 22 | 318489386884 |
| 23 | 1261428593649 |
| 24 | 5009356014722 |
| 25 | 19941674099985 |