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 | 0 |
| 2 | 4 |
| 3 | 20 |
| 4 | 39 |
| 5 | 175 |
| 6 | 779 |
| 7 | 1500 |
| 8 | 6664 |
| 9 | 29600 |
| 10 | 56979 |
| 11 | 253075 |
| 12 | 1124039 |
| 13 | 2163720 |
| 14 | 9610204 |
| 15 | 42683900 |
| 16 | 82164399 |
| 17 | 364934695 |
| 18 | 1620864179 |
| 19 | 3120083460 |
| 20 | 13857908224 |
| 21 | 61550154920 |
| 22 | 118481007099 |
| 23 | 526235577835 |
| 24 | 2337285022799 |
| 25 | 4499158186320 |
| 26 | 19983094049524 |
| 27 | 88755280711460 |
| 28 | 170849530073079 |
| 29 | 758831338304095 |
| 30 | 3370363382012699 |