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 | 9 |
| 2 | 21 |
| 3 | 57 |
| 4 | 129 |
| 5 | 249 |
| 6 | 429 |
| 7 | 681 |
| 8 | 1017 |
| 9 | 1449 |
| 10 | 1989 |
| 11 | 2649 |
| 12 | 3441 |
| 13 | 4377 |
| 14 | 5469 |
| 15 | 6729 |
| 16 | 8169 |
| 17 | 9801 |
| 18 | 11637 |
| 19 | 13689 |
| 20 | 15969 |
| 21 | 18489 |
| 22 | 21261 |
| 23 | 24297 |
| 24 | 27609 |
| 25 | 31209 |
| 26 | 35109 |
| 27 | 39321 |
| 28 | 43857 |
| 29 | 48729 |
| 30 | 53949 |
| 31 | 59529 |
| 32 | 65481 |
| 33 | 71817 |
| 34 | 78549 |
| 35 | 85689 |
| 36 | 93249 |
| 37 | 101241 |
| 38 | 109677 |
| 39 | 118569 |