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 | 9 |
| 2 | 51 |
| 3 | 219 |
| 4 | 786 |
| 5 | 2466 |
| 6 | 6974 |
| 7 | 18126 |
| 8 | 43929 |
| 9 | 100321 |
| 10 | 217683 |
| 11 | 451707 |
| 12 | 901128 |
| 13 | 1735752 |
| 14 | 3239928 |
| 15 | 5878328 |
| 16 | 10393902 |
| 17 | 17950878 |
| 18 | 30340682 |
| 19 | 50273658 |
| 20 | 81787476 |
| 21 | 130811124 |
| 22 | 205935756 |
| 23 | 319456044 |
| 24 | 488764246 |
| 25 | 738197766 |
| 26 | 1101468114 |
| 27 | 1624826306 |
| 28 | 2371158504 |
| 29 | 3425244456 |