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 | 30 |
| 2 | 364 |
| 3 | 1128 |
| 4 | 0 |
| 5 | 35604 |
| 6 | 462436 |
| 7 | 1516410 |
| 8 | 0 |
| 9 | 50331332 |
| 10 | 670671976 |
| 11 | 2244207954 |
| 12 | 0 |
| 13 | 76189204224 |
| 14 | 1028085663460 |
| 15 | 3477020782410 |
| 16 | 0 |
| 17 | 119558435601108 |
| 18 | 1625407357115064 |
| 19 | 5533419347709582 |
| 20 | 0 |
| 21 | 191835254536494250 |