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 | 13 |
| 3 | 51 |
| 4 | 167 |
| 5 | 503 |
| 6 | 1441 |
| 7 | 4007 |
| 8 | 10923 |
| 9 | 29355 |
| 10 | 78037 |
| 11 | 205659 |
| 12 | 538127 |
| 13 | 1399583 |
| 14 | 3621289 |
| 15 | 9327695 |
| 16 | 23931603 |
| 17 | 61186131 |
| 18 | 155949085 |
| 19 | 396369795 |
| 20 | 1004904695 |
| 21 | 2541896519 |
| 22 | 6416348209 |
| 23 | 16165610999 |
| 24 | 40657256571 |
| 25 | 102090514683 |
| 26 | 255968753125 |
| 27 | 640899345579 |
| 28 | 1602640560479 |