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 | 7 |
| 3 | 28 |
| 4 | 83 |
| 5 | 313 |
| 6 | 937 |
| 7 | 3114 |
| 8 | 9417 |
| 9 | 29614 |
| 10 | 94863 |
| 11 | 298327 |
| 12 | 987917 |
| 13 | 3162083 |
| 14 | 9893887 |
| 15 | 29983327 |
| 16 | 99483667 |
| 17 | 315432874 |
| 18 | 994927133 |
| 19 | 2999833327 |
| 20 | 9486778167 |
| 21 | 31464263856 |
| 22 | 99497231067 |
| 23 | 299998333327 |
| 24 | 999949483667 |
| 25 | 3160522105583 |
| 26 | 9892825177313 |
| 27 | 29999983333327 |