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 | 7 |
| 2 | 42 |
| 3 | 235 |
| 4 | 1262 |
| 5 | 6594 |
| 6 | 33780 |
| 7 | 170475 |
| 8 | 850230 |
| 9 | 4200130 |
| 10 | 20585228 |
| 11 | 100220718 |
| 12 | 485164988 |
| 13 | 2337145360 |
| 14 | 11210274408 |
| 15 | 53567616267 |
| 16 | 255110184486 |
| 17 | 1211287208346 |
| 18 | 5735765695260 |
| 19 | 27093982041546 |
| 20 | 127699233939684 |
| 21 | 600650635811532 |
| 22 | 2819989050992472 |
| 23 | 13216897613555550 |