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 | 3 |
| 2 | 6 |
| 3 | 18 |
| 4 | 48 |
| 5 | 144 |
| 6 | 414 |
| 7 | 1242 |
| 8 | 3678 |
| 9 | 11034 |
| 10 | 32958 |
| 11 | 98874 |
| 12 | 296208 |
| 13 | 888624 |
| 14 | 2664630 |
| 15 | 7993890 |
| 16 | 23977992 |
| 17 | 71933976 |
| 18 | 215790894 |
| 19 | 647372682 |
| 20 | 1942085088 |
| 21 | 5826255264 |
| 22 | 17478666918 |
| 23 | 52436000754 |
| 24 | 157307706054 |
| 25 | 471923118162 |