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 | 4 |
| 2 | 17 |
| 3 | 66 |
| 4 | 235 |
| 5 | 824 |
| 6 | 2848 |
| 7 | 9520 |
| 8 | 31648 |
| 9 | 104536 |
| 10 | 339553 |
| 11 | 1099666 |
| 12 | 3549038 |
| 13 | 11338836 |
| 14 | 36160324 |
| 15 | 115069316 |
| 16 | 363700188 |
| 17 | 1148126044 |
| 18 | 3619072821 |
| 19 | 11352513438 |
| 20 | 35579368776 |
| 21 | 111388887136 |
| 22 | 347450537496 |
| 23 | 1083054672896 |
| 24 | 3373317547471 |