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 | 4 |
| 4 | 10 |
| 5 | 26 |
| 6 | 76 |
| 7 | 206 |
| 8 | 546 |
| 9 | 1406 |
| 10 | 3608 |
| 11 | 9259 |
| 12 | 23981 |
| 13 | 62324 |
| 14 | 162224 |
| 15 | 422028 |
| 16 | 1096900 |
| 17 | 2848240 |
| 18 | 7394076 |
| 19 | 19196044 |
| 20 | 49844356 |
| 21 | 129443736 |
| 22 | 336182997 |
| 23 | 873106045 |
| 24 | 2267493182 |
| 25 | 5888625652 |
| 26 | 15292437454 |
| 27 | 39713590230 |
| 28 | 103134439084 |
| 29 | 267836774530 |
| 30 | 695564961926 |