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 | 0 |
| 2 | 1 |
| 3 | 7 |
| 4 | 27 |
| 5 | 101 |
| 6 | 337 |
| 7 | 1151 |
| 8 | 3843 |
| 9 | 12965 |
| 10 | 43773 |
| 11 | 148529 |
| 12 | 505605 |
| 13 | 1727771 |
| 14 | 5920823 |
| 15 | 20345445 |
| 16 | 70073901 |
| 17 | 241849929 |
| 18 | 836230109 |
| 19 | 2896104951 |
| 20 | 10044664507 |
| 21 | 34884102385 |
| 22 | 121293088909 |
| 23 | 422196245641 |
| 24 | 1471030361069 |
| 25 | 5130057477187 |
| 26 | 17905427995239 |