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 | 67 |
| 4 | 191 |
| 5 | 541 |
| 6 | 1487 |
| 7 | 4079 |
| 8 | 11173 |
| 9 | 30559 |
| 10 | 83137 |
| 11 | 226427 |
| 12 | 615919 |
| 13 | 1675771 |
| 14 | 4556771 |
| 15 | 12387481 |
| 16 | 33677717 |
| 17 | 91558231 |
| 18 | 248887319 |
| 19 | 676566619 |
| 20 | 1839125531 |
| 21 | 4999337929 |
| 22 | 13589640521 |
| 23 | 36940536917 |
| 24 | 100415101481 |
| 25 | 272957090657 |
| 26 | 741974865617 |
| 27 | 2016896970001 |