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 | 3 |
| 3 | 27 |
| 4 | 99 |
| 5 | 297 |
| 6 | 891 |
| 7 | 1683 |
| 8 | 5049 |
| 9 | 15147 |
| 10 | 31977 |
| 11 | 95931 |
| 12 | 225225 |
| 13 | 287793 |
| 14 | 675675 |
| 15 | 1091475 |
| 16 | 1576575 |
| 17 | 2027025 |
| 18 | 2297295 |
| 19 | 3828825 |
| 20 | 6185025 |
| 21 | 11486475 |
| 22 | 18555075 |
| 23 | 26801775 |
| 24 | 34459425 |
| 25 | 43648605 |
| 26 | 72747675 |
| 27 | 117515475 |
| 28 | 218243025 |
| 29 | 352546425 |
| 30 | 509233725 |
| 31 | 654729075 |
| 32 | 1003917915 |
| 33 | 1527701175 |
| 34 | 3011753745 |