Cr ( c, z, b, n, k ) = {
    if( z < b,  print1( c, " " );
        if( n>0, Cr( c+1, z  , b*  k  \n, n-1, k - 1 ))
    ,
        if( n>0, Cr( c+1, z-b, b*(n-k)\n, n-1, k     ))
    );
}

combR( n, k ) = {
    local(
        bnk = binomial( n,   k ),
        b11 = bnk * k \ n );          \\binomial( n-1, k-1 )
    for( z = 0,  bnk - 1,
        Cr( 1, z, b11, n-1, k-1 );
        print
    );
}