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 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 8 |
| 6 | 18 |
| 7 | 44 |
| 8 | 104 |
| 9 | 246 |
| 10 | 620 |
| 11 | 1600 |
| 12 | 4082 |
| 13 | 10436 |
| 14 | 27360 |
| 15 | 73046 |
| 16 | 193296 |
| 17 | 509984 |
| 18 | 1371214 |
| 19 | 3727792 |
| 20 | 10065872 |
| 21 | 27145058 |
| 22 | 74142688 |
| 23 | 204005440 |
| 24 | 558475342 |
| 25 | 1527058912 |
| 26 | 4213709856 |
| 27 | 11694035010 |
| 28 | 32331790700 |
| 29 | 89266126856 |
| 30 | 248240818282 |
| 31 | 693599213260 |