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 | 1 |
| 3 | 3 |
| 4 | 14 |
| 5 | 50 |
| 6 | 199 |
| 7 | 749 |
| 8 | 2892 |
| 9 | 11028 |
| 10 | 42301 |
| 11 | 161799 |
| 12 | 619706 |
| 13 | 2372006 |
| 14 | 9081955 |
| 15 | 34767953 |
| 16 | 133109592 |
| 17 | 509594856 |
| 18 | 1950956857 |
| 19 | 7469077707 |
| 20 | 28594853414 |
| 21 | 109473250778 |
| 22 | 419110475455 |
| 23 | 1604533706357 |
| 24 | 6142840740900 |
| 25 | 23517417426300 |