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 | 1 |
| 3 | 1 |
| 4 | 3 |
| 5 | 5 |
| 6 | 14 |
| 7 | 38 |
| 8 | 114 |
| 9 | 330 |
| 10 | 1054 |
| 11 | 3483 |
| 12 | 11841 |
| 13 | 41543 |
| 14 | 149520 |
| 15 | 552356 |
| 16 | 2084896 |
| 17 | 8046146 |
| 18 | 31649992 |
| 19 | 127031001 |
| 20 | 518434863 |
| 21 | 2153133594 |
| 22 | 9081863859 |
| 23 | 38909868272 |
| 24 | 169096646271 |
| 25 | 745348155211 |
| 26 | 3329032020048 |
| 27 | 15063018195100 |
| 28 | 68998386313333 |
| 29 | 319872246921326 |
| 30 | 1500013368166112 |