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 | 1 |
| 2 | 2 |
| 3 | 4 |
| 4 | 10 |
| 5 | 28 |
| 6 | 93 |
| 7 | 354 |
| 8 | 1621 |
| 9 | 9110 |
| 10 | 64801 |
| 11 | 595976 |
| 12 | 7204091 |
| 13 | 115561423 |
| 14 | 2473540433 |
| 15 | 70853213144 |
| 16 | 2720354016419 |
| 17 | 140170631441858 |
| 18 | 9702605436760235 |
| 19 | 903309202327818566 |
| 20 | 113234129823368903523 |
| 21 | 19137461395401601912043 |
| 22 | 4366007821745938984134203 |