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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 10 |
| 6 | 55 |
| 7 | 220 |
| 8 | 715 |
| 9 | 2003 |
| 10 | 5025 |
| 11 | 11650 |
| 12 | 25850 |
| 13 | 57475 |
| 14 | 134883 |
| 15 | 345090 |
| 16 | 952195 |
| 17 | 2722455 |
| 18 | 7765010 |
| 19 | 21615771 |
| 20 | 58293475 |
| 21 | 152593575 |
| 22 | 390679925 |
| 23 | 988851150 |
| 24 | 2502813930 |
| 25 | 6394182650 |
| 26 | 16569837550 |
| 27 | 43533891575 |
| 28 | 115440190725 |
| 29 | 307108317769 |
| 30 | 815362167365 |