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 | 3 |
| 1 | 7 |
| 2 | 27 |
| 3 | 71 |
| 4 | 267 |
| 5 | 703 |
| 6 | 2643 |
| 7 | 6959 |
| 8 | 26163 |
| 9 | 68887 |
| 10 | 258987 |
| 11 | 681911 |
| 12 | 2563707 |
| 13 | 6750223 |
| 14 | 25378083 |
| 15 | 66820319 |
| 16 | 251217123 |
| 17 | 661452967 |
| 18 | 2486793147 |
| 19 | 6547709351 |
| 20 | 24616714347 |
| 21 | 64815640543 |
| 22 | 243680350323 |
| 23 | 641608696079 |
| 24 | 2412186788883 |
| 25 | 6351271320247 |
| 26 | 23878187538507 |