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) |
|---|---|
| 3 | 26 |
| 4 | 58 |
| 5 | 182 |
| 6 | 540 |
| 7 | 1290 |
| 8 | 3690 |
| 9 | 10160 |
| 10 | 28786 |
| 11 | 80841 |
| 12 | 223888 |
| 13 | 624613 |
| 14 | 1743972 |
| 15 | 4865441 |
| 16 | 13595466 |
| 17 | 37944869 |
| 18 | 105893100 |
| 19 | 295608956 |
| 20 | 825144438 |
| 21 | 2303387028 |
| 22 | 6429909987 |
| 23 | 17948364550 |
| 24 | 50101571688 |
| 25 | 139855118057 |
| 26 | 390395847523 |
| 27 | 1089765919988 |
| 28 | 3042007560076 |
| 29 | 8491555206270 |