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 | 1 |
| 1 | 3 |
| 2 | 15 |
| 3 | 64 |
| 4 | 276 |
| 5 | 1137 |
| 6 | 4648 |
| 7 | 18585 |
| 8 | 73494 |
| 9 | 286834 |
| 10 | 1108470 |
| 11 | 4243128 |
| 12 | 16111333 |
| 13 | 60718488 |
| 14 | 227302086 |
| 15 | 845689753 |
| 16 | 3128786415 |
| 17 | 11515509603 |
| 18 | 42179651417 |
| 19 | 153808740042 |
| 20 | 558532554942 |
| 21 | 2020325112767 |
| 22 | 7281212274165 |
| 23 | 26151068072301 |
| 24 | 93618849857345 |
| 25 | 334119804933861 |