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 | 30 |
| 5 | 2065 |
| 6 | 51926 |
| 7 | 691686 |
| 8 | 6185741 |
| 9 | 42149926 |
| 10 | 235537736 |
| 11 | 1130582442 |
| 12 | 4808698802 |
| 13 | 18525169347 |
| 14 | 65689136552 |
| 15 | 217026359262 |
| 16 | 674420929513 |
| 17 | 1986166442853 |
| 18 | 5577112808148 |
| 19 | 15006708704808 |
| 20 | 38855732384838 |
| 21 | 97150869913209 |
| 22 | 235268421882814 |
| 23 | 553258656221514 |