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 | 0 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 13 |
| 6 | 38 |
| 7 | 118 |
| 8 | 380 |
| 9 | 1262 |
| 10 | 4277 |
| 11 | 14745 |
| 12 | 51541 |
| 13 | 182182 |
| 14 | 650095 |
| 15 | 2338706 |
| 16 | 8472697 |
| 17 | 30884150 |
| 18 | 113189168 |
| 19 | 416839177 |
| 20 | 1541726967 |
| 21 | 5724470097 |
| 22 | 21330062502 |
| 23 | 79733319862 |
| 24 | 298922247363 |
| 25 | 1123678419818 |
| 26 | 4234465089737 |
| 27 | 15993581636893 |
| 28 | 60535561889465 |