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 | 1 |
| 1 | 1 |
| 2 | 1 |
| 3 | 2 |
| 4 | 4 |
| 5 | 10 |
| 6 | 26 |
| 7 | 71 |
| 8 | 197 |
| 9 | 564 |
| 10 | 1639 |
| 11 | 4833 |
| 12 | 14406 |
| 13 | 43374 |
| 14 | 131652 |
| 15 | 402525 |
| 16 | 1238419 |
| 17 | 3831520 |
| 18 | 11912913 |
| 19 | 37204431 |
| 20 | 116655147 |
| 21 | 367100319 |
| 22 | 1159026041 |
| 23 | 3670339794 |
| 24 | 11655070593 |
| 25 | 37104257405 |
| 26 | 118398974620 |
| 27 | 378627600346 |
| 28 | 1213247498254 |
| 29 | 3894924465243 |