Shared via Rust Playground

playground.rs

fn v(n: u32) -> u32 {
    match n {
        0 => 1,
        _ => 3*c(n-1),
    }
}

fn c(n: u32) -> u32 {
    match n {
        0 => 1,
        _ => 2*v(n-1) + 2*c(n-1),
    }
}

fn main() {
    println!("{}", 2*v(9));
}