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 | 0 |
| 1 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 7 |
| 6 | 33 |
| 7 | 131 |
| 8 | 473 |
| 9 | 1608 |
| 10 | 5242 |
| 11 | 16567 |
| 12 | 51123 |
| 13 | 154793 |
| 14 | 461525 |
| 15 | 1358646 |
| 16 | 3957088 |
| 17 | 11420995 |
| 18 | 32707809 |
| 19 | 93040751 |
| 20 | 263113505 |
| 21 | 740238852 |
| 22 | 2073098086 |
| 23 | 5782387855 |
| 24 | 16070206191 |
| 25 | 44516728277 |
| 26 | 122956408493 |
| 27 | 338707969266 |
| 28 | 930787894348 |
| 29 | 2552224341403 |
| 30 | 6984100641117 |