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 | 5 |
| 2 | 30 |
| 3 | 140 |
| 4 | 490 |
| 5 | 1491 |
| 6 | 3976 |
| 7 | 9696 |
| 8 | 21816 |
| 9 | 46126 |
| 10 | 92252 |
| 11 | 176232 |
| 12 | 323092 |
| 13 | 571802 |
| 14 | 980232 |
| 15 | 1633984 |
| 16 | 2655224 |
| 17 | 4217499 |
| 18 | 6560554 |
| 19 | 10014004 |
| 20 | 15021006 |
| 21 | 22174581 |
| 22 | 32253936 |
| 23 | 46278336 |
| 24 | 65560976 |
| 25 | 91786604 |
| 26 | 127089144 |
| 27 | 174160784 |
| 28 | 236361064 |
| 29 | 317866884 |
| 30 | 423822512 |