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 | 4 |
| 4 | 13 |
| 5 | 62 |
| 6 | 297 |
| 7 | 1523 |
| 8 | 8091 |
| 9 | 43243 |
| 10 | 234347 |
| 11 | 1267141 |
| 12 | 6814076 |
| 13 | 36368431 |
| 14 | 192079140 |
| 15 | 1006805203 |
| 16 | 5262612068 |
| 17 | 27656507707 |
| 18 | 147973596219 |
| 19 | 815825605806 |
| 20 | 4662818005761 |
| 21 | 27504894986209 |
| 22 | 165036600363916 |
| 23 | 989160502170958 |
| 24 | 5829789341752240 |
| 25 | 33444482725193880 |