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 | 1 |
| 3 | 2 |
| 4 | 5 |
| 5 | 9 |
| 6 | 40 |
| 7 | 111 |
| 8 | 643 |
| 9 | 2261 |
| 10 | 6176 |
| 11 | 53560 |
| 12 | 265001 |
| 13 | 976535 |
| 14 | 10699235 |
| 15 | 65839306 |
| 16 | 297528021 |
| 17 | 1096638993 |
| 18 | 16254932942 |
| 19 | 131192702293 |
| 20 | 760059358527 |
| 21 | 3527632148650 |
| 22 | 63700463354263 |
| 23 | 620906514026512 |
| 24 | 4309068955961383 |
| 25 | 23776534616426566 |
| 26 | 110660256825406666 |