Generates Norwegian FH numbers (Felles Hjelpenummer) - 11 digit ids used at hospitals for tourists and people without ids

fhnumber.js

// original: https://gist.github.com/a849ca8a75eb4b5e35cd1af700435875

// The two checksum series.
// for digit 10, the first check digit
const checksumSeries1 = [3, 7, 6, 1, 8, 9, 4, 5, 2, 1]; // 10 digits
// for digit 11, the 2nd check digit
const checksumSeries2 = [5, 4, 3, 2, 7, 6, 5, 4, 3, 2, 1]; // 11 digits

function sumDigits(number, checksumSeries) {
    // Split into array of digits
    const digits = number.toString().split('').map(d => parseInt(d, 10));

    let sum = 0;
    for (let i = 0; i < checksumSeries.length; ++i) {
        sum += digits[i] * checksumSeries[i];
    }

    return sum;
}

function generateValidNumbers(startingDigitString){
    const digitsToGenerate = 11 - startingDigitString.length;
    const numberSeriesUpperBound = Math.pow(10, digitsToGenerate);
    let id;
    let i = Math.pow(10, digitsToGenerate - 1);

    while(i++ < numberSeriesUpperBound) {
        id = startingDigitString + i;
        const rest1 = sumDigits(id, checksumSeries1) % 11

        if(rest1 === 0) {
            const rest2 = sumDigits(id, checksumSeries2) % 11
            if(rest2 === 0) 
                console.log(id);
        }
    }
}

function generateFhNumbers(){
    generateValidNumbers('8');
}

function generateNormalNationalIds() {
    // just generate 
}

generateFhNumbers();