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 | 1 |
| 2 | 3 |
| 3 | 10 |
| 4 | 39 |
| 5 | 171 |
| 6 | 822 |
| 7 | 4271 |
| 8 | 23759 |
| 9 | 140518 |
| 10 | 878883 |
| 11 | 5789015 |
| 12 | 40019058 |
| 13 | 289513303 |
| 14 | 2186421919 |
| 15 | 17199606090 |
| 16 | 140662816543 |
| 17 | 1193865048363 |
| 18 | 10499107480518 |
| 19 | 95528651305671 |
| 20 | 898071593401559 |
| 21 | 8712429618413678 |
| 22 | 87118795125708283 |
| 23 | 896925422648691735 |