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 | 0 |
| 2 | 5 |
| 3 | 15 |
| 4 | 40 |
| 5 | 105 |
| 6 | 275 |
| 7 | 720 |
| 8 | 1885 |
| 9 | 4935 |
| 10 | 12920 |
| 11 | 33825 |
| 12 | 88555 |
| 13 | 231840 |
| 14 | 606965 |
| 15 | 1589055 |
| 16 | 4160200 |
| 17 | 10891545 |
| 18 | 28514435 |
| 19 | 74651760 |
| 20 | 195440845 |
| 21 | 511670775 |
| 22 | 1339571480 |
| 23 | 3507043665 |
| 24 | 9181559515 |
| 25 | 24037634880 |
| 26 | 62931345125 |
| 27 | 164756400495 |
| 28 | 431337856360 |
| 29 | 1129257168585 |