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 | 0 |
| 2 | 0 |
| 3 | 0 |
| 4 | 1 |
| 5 | 7 |
| 6 | 28 |
| 7 | 84 |
| 8 | 211 |
| 9 | 476 |
| 10 | 1029 |
| 11 | 2276 |
| 12 | 5384 |
| 13 | 13594 |
| 14 | 35371 |
| 15 | 91667 |
| 16 | 232681 |
| 17 | 577710 |
| 18 | 1413462 |
| 19 | 3442498 |
| 20 | 8414484 |
| 21 | 20717963 |
| 22 | 51346109 |
| 23 | 127678961 |
| 24 | 317496621 |
| 25 | 787941379 |
| 26 | 1950774874 |
| 27 | 4821609252 |
| 28 | 11910608942 |
| 29 | 29432604429 |
| 30 | 72787392898 |
| 31 | 180131835001 |