In recreational mathematics, a Harshad number (or Niven number) in a given number base, is an integer that is divisible by the sum of its digits when written in that base. Harshad numbers in base n are also known as n-Harshad (or n-Niven) numbers. Harshad numbers were defined by D. R. Kaprekar, a mathematician from India.

Java Code assuming base 10:

```1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 public class HarshadNumber { public static void main(String[] args) { long seq = 100; //limit the seq of harshad numbers int num, sum; for (int i = 1; i <= seq; i++) { num = i; sum = 0; while (num != 0) { sum += num % 10; num = num / 10; } if (i % sum == 0) { System.out.println(i); } } } }```

Output: 1,2,3,4,5,6,7,8,9,10,12,18,20,21,24,27,30,36,40,42,45,48,50,54,60,63,70,72,80,81,84,90,100

Javascript Code assuming base 10:

```1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 var i,num,sum,temp,limit=100; for(i=1;i<=limit;i++){ num = i; sum = 0; temp = 0; while(num!=0){ sum+=num%10; temp = num/10; //observe the use of toFixed and floor functions //They are necessary here to get the desired result // Example: var a = 5/10 // a==0.5 // a.toFixed() = "1" // Math.floor(a) = 0 num=(Math.floor(temp)).toFixed(); } if(i%sum == 0){ console.log(i); } }```
“Without mathematics, there’s nothing you can do. Everything around you is mathematics. Everything around you is numbers.”
-Shakuntala Devi