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 | 2 |
| 2 | 9 |
| 3 | 24 |
| 4 | 88 |
| 5 | 280 |
| 6 | 1064 |
| 7 | 3672 |
| 8 | 14456 |
| 9 | 52184 |
| 10 | 210504 |
| 11 | 782232 |
| 12 | 3210904 |
| 13 | 12176792 |
| 14 | 50638440 |
| 15 | 194956248 |
| 16 | 818961080 |
| 17 | 3189915224 |
| 18 | 13508052104 |
| 19 | 53105011480 |
| 20 | 226355549400 |
| 21 | 896636646936 |
| 22 | 3842662060200 |
| 23 | 15317408281944 |
| 24 | 65946510374136 |