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 | 14 |
| 2 | 64 |
| 3 | 236 |
| 4 | 1012 |
| 5 | 4384 |
| 6 | 19486 |
| 7 | 87738 |
| 8 | 399372 |
| 9 | 1832672 |
| 10 | 8464954 |
| 11 | 39306138 |
| 12 | 183315034 |
| 13 | 858086906 |
| 14 | 4029197992 |
| 15 | 18969932356 |
| 16 | 89518725372 |
| 17 | 423283210304 |
| 18 | 2004963114682 |
| 19 | 9511428021442 |
| 20 | 45182292435262 |
| 21 | 214884038667702 |