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 | 1 |
| 1 | 1 |
| 2 | 4 |
| 3 | 10 |
| 4 | 26 |
| 5 | 69 |
| 6 | 181 |
| 7 | 476 |
| 8 | 1252 |
| 9 | 3292 |
| 10 | 8657 |
| 11 | 22765 |
| 12 | 59864 |
| 13 | 157422 |
| 14 | 413966 |
| 15 | 1088589 |
| 16 | 2862617 |
| 17 | 7527704 |
| 18 | 19795288 |
| 19 | 52054840 |
| 20 | 136886433 |
| 21 | 359964521 |
| 22 | 946583628 |
| 23 | 2489191330 |
| 24 | 6545722210 |
| 25 | 17213011605 |
| 26 | 45264335853 |
| 27 | 119029728628 |