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) |
|---|---|
| 1 | 2 |
| 2 | 2 |
| 3 | 4 |
| 4 | 8 |
| 5 | 20 |
| 6 | 42 |
| 7 | 100 |
| 8 | 228 |
| 9 | 540 |
| 10 | 1278 |
| 11 | 3088 |
| 12 | 7436 |
| 13 | 18176 |
| 14 | 44436 |
| 15 | 109536 |
| 16 | 270726 |
| 17 | 672400 |
| 18 | 1674764 |
| 19 | 4185888 |
| 20 | 10488914 |
| 21 | 26352252 |
| 22 | 66354472 |
| 23 | 167429028 |
| 24 | 423270120 |
| 25 | 1071908028 |
| 26 | 2718939372 |
| 27 | 6906918040 |
| 28 | 17569856618 |
| 29 | 44751600732 |
| 30 | 114121225984 |
| 31 | 291346481204 |
| 32 | 744569863528 |