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 | 1 |
| 2 | 3 |
| 3 | 7 |
| 4 | 18 |
| 5 | 38 |
| 6 | 100 |
| 7 | 224 |
| 8 | 600 |
| 9 | 1498 |
| 10 | 4124 |
| 11 | 11054 |
| 12 | 31347 |
| 13 | 87887 |
| 14 | 253251 |
| 15 | 727867 |
| 16 | 2117551 |
| 17 | 6159994 |
| 18 | 18022052 |
| 19 | 52757222 |
| 20 | 154874172 |
| 21 | 454989753 |
| 22 | 1338737083 |
| 23 | 3941860229 |
| 24 | 11618101775 |
| 25 | 34264747423 |
| 26 | 101127761931 |
| 27 | 298632667837 |
| 28 | 882370316215 |
| 29 | 2608423280534 |
| 30 | 7714578529582 |