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      "source": [
        "# Fibonacci Solver\n",
        "\n",
        "The Fibonacci Sequence is the series of numbers:\n",
        "\n",
        "` 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, ... `\n",
        "\n",
        "The next number is found by adding up the two numbers before it:\n",
        "\n",
        "the `2` is found by adding the two numbers before it `(1+1)`,\n",
        "the `3` is found by adding the two numbers before it `(1+2)`,\n",
        "the `5` is `(2+3)`,\n",
        "and so on!\n",
        "\n",
        "## Coding it up in Python\n",
        "Just initialize to variables with the first two numbers of the Fibonacci sequence. Then add them up and print the result.\n"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "p58ac2HULNWv"
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      "source": [],
      "execution_count": null,
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    {
      "cell_type": "markdown",
      "metadata": {
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      "source": [
        "You now need to do this multiple times, so you need a ***loop***\n",
        "To use a loop you need to know how many times you want to loop for.  \n",
        "For now, create a loop that prints **20** numbers (from 0 to 19). To do this in python you can create a ***for loop*** using the `range` function which will run the function for every number in the range.\n",
        "(TIP: Python is a ***0 based*** language which means it starts counting from 0 not 1 as a human normally would.)"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
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      "source": [],
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    {
      "cell_type": "markdown",
      "metadata": {
        "id": "INNU9p8zLNW0"
      },
      "source": [
        "Now use the loop to compute the first 20 elements of the Fibonacci sequence."
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "4Hf59jqgLNW1"
      },
      "source": [],
      "execution_count": null,
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    {
      "cell_type": "markdown",
      "metadata": {
        "id": "bScJ-6tULNW3"
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      "source": [
        "If you managed it till here great job!\n",
        "Is seems to work great so far, but you need to store these numbers so you can reference them when needed."
      ]
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "1VhirrXpLNW3"
      },
      "source": [
        "Create an empty ***array*** called `fibonacci` and then append the elements of the sequence to it."
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "thTMoVY2LNW3"
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      "source": [],
      "execution_count": null,
      "outputs": []
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      "cell_type": "markdown",
      "metadata": {
        "id": "6nlc_cC7LNW5"
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      "source": [
        "If everything worked according to the plan, you should be able to access any of the first 20 elements of the Fibonacci sequence at will.\n",
        "\n",
        "eg `fibonacci[0]` would get us the first item in the array whilst `fibonacci[9]` would get us the tenth item (remember Python is 0 based so you always need to take 1 away from the number you need)"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "yEKa7pAuLNW6"
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      "source": [
        "fibonacci[0]"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "1wbxOVnELNW7"
      },
      "source": [
        "fibonacci[9]"
      ],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "50FpCM7CLNW9"
      },
      "source": [
        "So now you know how to get at the index, you need to know which index values are asked for by the user.\n",
        "Lets get some input from the user."
      ]
    },
    {
      "cell_type": "markdown",
      "source": [
        "Get the first index from the user"
      ],
      "metadata": {
        "id": "5Vp9iO2r2e2S"
      }
    },
    {
      "cell_type": "code",
      "source": [],
      "metadata": {
        "id": "Zj6mnXCI2mNo"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "source": [
        "Get the second index from the user"
      ],
      "metadata": {
        "id": "9LDXbzP02rFa"
      }
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "wqbTuR2TLNXA"
      },
      "source": [],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "source": [
        "Print the received inputs and their types"
      ],
      "metadata": {
        "id": "EK9FMjJV22x9"
      }
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "xfy81HrsLNXC"
      },
      "source": [],
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
        "id": "ttb_0MejLNXE"
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      "source": [
        "The value received from input will be treated as a string type, you need to convert this to a number so python knows to treat it as one."
      ]
    },
    {
      "cell_type": "code",
      "source": [],
      "metadata": {
        "id": "RwVoHTLn6QvB"
      },
      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "source": [
        "Print the type of the transformed variables."
      ],
      "metadata": {
        "id": "pxKx8gKy2-eh"
      }
    },
    {
      "cell_type": "code",
      "source": [],
      "metadata": {
        "id": "dN_EzHKr3GmO"
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      "execution_count": null,
      "outputs": []
    },
    {
      "cell_type": "markdown",
      "metadata": {
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      "source": [
        "Now you have all the parts you need to make this work. \n",
        "\n",
        "*   The user should be prompted \"How many results would you like?\"\n",
        "*   The program should read the users preference, e.g. 20, and then compute the list of elements up to this number.\n",
        "*   Then the program should ask the user for 2 indexes within the list of the calculated Fibonacci sequence\n",
        "*   Finally it should print the summation of their values.\n",
        "\n",
        "Time to put it together:"
      ]
    },
    {
      "cell_type": "code",
      "metadata": {
        "id": "ukW0WUA7LNXE"
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      "source": [],
      "execution_count": null,
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