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 | 1 |
| 2 | 6 |
| 3 | 31 |
| 4 | 160 |
| 5 | 841 |
| 6 | 4494 |
| 7 | 24319 |
| 8 | 132864 |
| 9 | 731281 |
| 10 | 4048726 |
| 11 | 22523359 |
| 12 | 125797984 |
| 13 | 704966809 |
| 14 | 3961924126 |
| 15 | 22321190911 |
| 16 | 126027618304 |
| 17 | 712917362209 |
| 18 | 4039658528934 |
| 19 | 22924714957471 |
| 20 | 130271906898720 |
| 21 | 741188107113961 |
| 22 | 4221707080583086 |
| 23 | 24070622500965631 |
| 24 | 137369104574280960 |
| 25 | 784622537295845041 |