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 | 3 |
| 2 | 9 |
| 3 | 30 |
| 4 | 60 |
| 5 | 179 |
| 6 | 353 |
| 7 | 1046 |
| 8 | 2060 |
| 9 | 6099 |
| 10 | 12009 |
| 11 | 35550 |
| 12 | 69996 |
| 13 | 207203 |
| 14 | 407969 |
| 15 | 1207670 |
| 16 | 2377820 |
| 17 | 7038819 |
| 18 | 13858953 |
| 19 | 41025246 |
| 20 | 80775900 |
| 21 | 239112659 |
| 22 | 470796449 |
| 23 | 1393650710 |
| 24 | 2744002796 |
| 25 | 8122791603 |
| 26 | 15993220329 |
| 27 | 47343098910 |
| 28 | 93215319180 |
| 29 | 275935801859 |