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 | 3 |
| 2 | 9 |
| 3 | 20 |
| 4 | 40 |
| 5 | 77 |
| 6 | 147 |
| 7 | 282 |
| 8 | 546 |
| 9 | 1067 |
| 10 | 2101 |
| 11 | 4160 |
| 12 | 8268 |
| 13 | 16473 |
| 14 | 32871 |
| 15 | 65654 |
| 16 | 131206 |
| 17 | 262295 |
| 18 | 524457 |
| 19 | 1048764 |
| 20 | 2097360 |
| 21 | 4194533 |
| 22 | 8388859 |
| 23 | 16777490 |
| 24 | 33554730 |
| 25 | 67109187 |
| 26 | 134218077 |
| 27 | 268435832 |
| 28 | 536871316 |
| 29 | 1073742257 |
| 30 | 2147484111 |