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 | 5 |
| 4 | 15 |
| 5 | 53 |
| 6 | 215 |
| 7 | 979 |
| 8 | 4922 |
| 9 | 26992 |
| 10 | 159958 |
| 11 | 1016784 |
| 12 | 6890723 |
| 13 | 49534501 |
| 14 | 376081602 |
| 15 | 3004503758 |
| 16 | 25175290576 |
| 17 | 220624253707 |
| 18 | 2017049937115 |
| 19 | 19195118759579 |
| 20 | 189758808470023 |
| 21 | 1945188215493411 |
| 22 | 20642140342300062 |
| 23 | 226427702583430619 |
| 24 | 2563833140546044096 |