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 | 13 |
| 3 | 36 |
| 4 | 158 |
| 5 | 708 |
| 6 | 4236 |
| 7 | 26412 |
| 8 | 180070 |
| 9 | 1256914 |
| 10 | 8999762 |
| 11 | 65225244 |
| 12 | 477772294 |
| 13 | 3525803320 |
| 14 | 26185264801 |
| 15 | 195490126328 |
| 16 | 1466095545930 |
| 17 | 11038514989344 |
| 18 | 83401050695432 |
| 19 | 632087998742988 |
| 20 | 4803854169636124 |
| 21 | 36600736833265244 |
| 22 | 279496328812771427 |