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 | 5 |
| 2 | 19 |
| 3 | 57 |
| 4 | 175 |
| 5 | 537 |
| 6 | 1653 |
| 7 | 5089 |
| 8 | 15663 |
| 9 | 48207 |
| 10 | 148375 |
| 11 | 456685 |
| 12 | 1405633 |
| 13 | 4326401 |
| 14 | 13316243 |
| 15 | 40986117 |
| 16 | 126151337 |
| 17 | 388281713 |
| 18 | 1195093865 |
| 19 | 3678384289 |
| 20 | 11321714051 |
| 21 | 34847150005 |
| 22 | 107256185601 |
| 23 | 330124252601 |
| 24 | 1016090788147 |
| 25 | 3127429995345 |