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 | 7 |
| 1 | 23 |
| 2 | 71 |
| 3 | 215 |
| 4 | 647 |
| 5 | 1943 |
| 6 | 5831 |
| 7 | 17495 |
| 8 | 52487 |
| 9 | 157463 |
| 10 | 472391 |
| 11 | 1417175 |
| 12 | 4251527 |
| 13 | 12754583 |
| 14 | 38263751 |
| 15 | 114791255 |
| 16 | 344373767 |
| 17 | 1033121303 |
| 18 | 3099363911 |
| 19 | 9298091735 |
| 20 | 27894275207 |
| 21 | 83682825623 |
| 22 | 251048476871 |
| 23 | 753145430615 |
| 24 | 2259436291847 |
| 25 | 6778308875543 |
| 26 | 20334926626631 |
| 27 | 61004779879895 |