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) |
|---|---|
| 0 | 1 |
| 1 | 3 |
| 2 | 9 |
| 3 | 24 |
| 4 | 60 |
| 5 | 141 |
| 6 | 324 |
| 7 | 717 |
| 8 | 1560 |
| 9 | 3330 |
| 10 | 7020 |
| 11 | 14622 |
| 12 | 30225 |
| 13 | 61998 |
| 14 | 126522 |
| 15 | 257007 |
| 16 | 520326 |
| 17 | 1050396 |
| 18 | 2116116 |
| 19 | 4255584 |
| 20 | 8547330 |
| 21 | 17149350 |
| 22 | 34382295 |
| 23 | 68889840 |
| 24 | 137969466 |
| 25 | 276220962 |
| 26 | 552865365 |
| 27 | 1106356314 |
| 28 | 2213644548 |
| 29 | 4428657402 |
| 30 | 8859340926 |
| 31 | 17721640698 |