Matrices

// example:
//[ [ 16, 32, 64, 128, 256, 512 ],
//    [ 8, 16, 32, 64, 128, 256 ],
//    [ 4, 8, 16, 32, 64, 128 ],
//    [ 2, 4, 8, 16, 32, 64 ],
//    [ 1, 2, 4, 8, 16, 32 ] ]

function fillMatrix(rows, cols){
    var matrix = [];
    for (var row = rows - 1; row >= 0; row -= 1) {
        matrix[row] = [];
        for (var col = 0; col < cols; col += 1) {
            matrix[row][col] = Math.pow(2, col + (rows - row) - 1);
        }
    }

    return matrix;
}

// example:
//[ [ 15, 18, 21, 24, 27, 30, 33 ],
//    [ 12, 15, 18, 21, 24, 27, 30 ],
//    [ 9, 12, 15, 18, 21, 24, 27 ],
//    [ 6, 9, 12, 15, 18, 21, 24 ],
//    [ 3, 6, 9, 12, 15, 18, 21 ],
//    [ 0, 3, 6, 9, 12, 15, 18 ] ]

function fillMatrix(rows, cols) {
    var matrix = [];
    for (var row = rows - 1; row >= 0; row -= 1) {
        matrix[row] = [];
        for (var col = 0; col < cols; col += 1) {
            matrix[row][col] = (rows - 1 - row + col) * 3
        }
    }

    return matrix;
}